Talk:18 (number)

Removed

• It is considered a number of the devil due to the fact that 6+6+6=18, and 666 is the number of the beast, as described in chapter 13, verse 18 of the Book of Revelation. There are also 18 letters in the words six-hundred sixty six.

I removed this for numerous reasons, first of all a simple search of "18 is a number of the devil" or "18 is a number of the beast" or "18 is the number of the devil" or "18 is the number of the beast" returns no results at all on Google.com. Also non of the other languages articles mention this, including languages spoken by perhaps more Christian inclined people (Spanish, Italian).

Also in "six-hundred and sixty six" there is 21 letters! No evidence to show anywhere that it is a "demonic" number of even believed to be. - S.Azzopardi (talk) 05:29, 6 February 2008 (UTC)

True, but to be pedantic and fair to the user, he did say "six-hundred sixty six" which does have eighteen letters; without the "and" is how it is frequently said (insisted upon in school) in the USA. That to one side, though, i've never heard of the suggestion that eighteen is an evil number. Cheers, Lindsay 17:07, 14 February 2008 (UTC)

arabic?

What in the world is that passage talking about with the right hand and arabic? Can someone explain it? —Preceding unsigned comment added by 79.123.44.20 (talk) 14:30, 14 January 2010 (UTC)

Good catch. I've figured out what the passage was supposed to mean and changed it to be easier to understand. --Florian Blaschke (talk) 23:42, 7 July 2011 (UTC)

Second paragraph

I find the second paragraph, about the pronunciation of 18 vs 80, to be unnecessary, or at least unnecessary in the introduction of the article. Should this paragraph be scaled down or removed all together? — Preceding unsigned comment added by Sheepythemouse (talk • contribs) 19:18, 24 March 2016 (UTC)

Retired jersey numbers

Per WP:PRESERVE, here is the list of retired #18 jersey numbers and racecars that were mentioned in the article:

• The jersey number 18 has been retired by several North American sports teams in honor of past playing greats or other key figures:
  • In Major League Baseball:
    • The Cincinnati Reds, for Ted Kluszewski.
    • The Cleveland Indians, for Mel Harder.
  • In the NBA:
    • The Boston Celtics, for Hall of Famer Dave Cowens. The team initially planned to retire the number for Jim Loscutoff, but he requested that the number not be retired at that time.
  • In the NHL:
    • The Buffalo Sabres, for Danny Gare.
    • The Chicago Blackhawks, for Hall of Famer Denis Savard.
    • The Montreal Canadiens, for Hall of Famer Serge Savard.
    • The Los Angeles Kings, for Dave Taylor.
  • In the NFL:
    • The Denver Broncos, for Frank Tripucka. The number was taken out of retirement, with Tripucka's blessing, for Peyton Manning, who wore the number with the Indianapolis Colts.
    • The Kansas City Chiefs, for Hall of Famer Emmitt Thomas.
    • The Colts have yet to retire any numbers during their history in Indianapolis, but have taken #18 out of circulation following Manning's departure from the team.
  • In addition, the University of Mississippi football program has retired #18 for Archie Manning.

• 18 is the number of a NASCAR Sprint Cup Series car currently owned by Joe Gibbs Racing. The #18 has been driven by Kyle Busch since 2008. Other notable drivers of the car include Dale Jarrett, who won the 1993 Daytona 500 in the #18; Bobby Labonte, who won the Cup championship in 2000; and J. J. Yeley.
• In Formula One, the number 18 is used by Canadian driver, Lance Stroll, who drives for Williams F1 Team.

This material may be of interest for a future List of retired numbers in sports article. — JFG ^talk 22:42, 16 May 2017 (UTC)

Neo-nazis

I believe 18 does have a meaning in a neo-Nazi context, but ADL is too biased to be a reliable source. Perhaps someone could copy in the BBC source used in the Combat 18 article? (Reference 1, not Reference 2, which should be a note requiring a reference.) — Arthur Rubin (talk) 19:42, 29 April 2018 (UTC)

Bingo names -

Please see Wikipedia talk:WikiProject Numbers#List of British bingo nicknames for a centralized discusion as to whether Bingo names should be included in thiese articles. Arthur Rubin (alternate) (talk) 23:33, 3 June 2018 (UTC)

Problem paragraph

As part of the ongoing kerfuffle, XOR'easter (best wishes, btw) restored the following paragraph:

• 18 is the sum-of-divisors of 10 (the only number to have this sum, aside from the prime number 17). [cite OEIS]

I do not think this is a good addition; I believe it is completely true, but so is the following paragraph:

• 18 is the second number (after 12) to be the sum-of-divisors of more than one number, viz. 10 and 17.

These two statements are simply different angles on the same trivial facts. I do not believe that citing OEIS in this way is helpful or necessary - after all you can check that the statements are true without a pocket calculator, you just need a piece of paper, a pencil, and n minutes for some small n. Unless you think that the bare fact that 18 is the SOD of 10 and 17 is noteworthy, just as a large fraction of all integers are the SOD of one or more numbers, I do not see that either of these embellishments is notable. I think that OEIS really is a problem if used to support *notability*. Imaginatorium (talk) 07:53, 11 August 2024 (UTC)

Discuss current mathematics content

Evaluating the current mathematics content of the article.

I believe all points curently on this page are notable. 18 as the sum-of-divisors of 10 (only one solution) is notable for it being a unique solution in an OEIS nice sequence (and not predictable in any sense). Regarding the point on pentominoes, I'm not convinced that it should not be included because of "WP:NROUTINE", as it is a non-routine solution for pentominoes, where 18 is not a solution for any other set of polyominoes, with any of the relevant symmetries considered (with holes, without holes, one-sided, or fixed). The numbering of finite simple groups that are Lie groups is clearly 18, and an important enumeration very often cited. "18 imaginary quadratic fields with class number 2" is also a count that is notable on its own regarding the imaginary quadratic fields of class 2 (when we also count the nine "Heegner numbers"). (All of these additions were kept by at least one other editor, aside from myself, meaning there is also agreement to keep; at least from recent input from editors.) Radlrb (talk) 03:03, 15 August 2024 (UTC)

Have you read my paragraph above? Imaginatorium (talk) 12:47, 15 August 2024 (UTC)

Yes, we can talk about all of the relevant points here. I gave my opinion about it here. I happened to see that paragraph right as I decided to write this topic. Let's converse, then. Radlrb (talk) 16:21, 15 August 2024 (UTC)

OK, converse. Have you read my argument? Can you see any flaw in it? You write "...sum-of-divisors of 10 (only one solution)", which does not seem very clear to me, but if I guess at its meaning, it is simply false. Please also refrain from pumping out the "at least one person did not delete it, therefore there is agreement (or whatever) to keep it" stuff. Imaginatorium (talk) 17:20, 15 August 2024 (UTC)

I said, there is also agreement to keep, not "consensus". Two different meanings. I did show you my point of view, that it is a singular *non-trivial* Radlrb (talk) 18:08, 15 August 2024 (UTC) solution regarding that very point, and therefore I believe it is worth including; not in any way "routine", it is on topic, about the number 18. It is not false in meaning, only one number aside from 17 (the trivial case, since it is prime) has a sum of divisors that is 10. Radlrb (talk) 17:34, 15 August 2024 (UTC)

Your response suggests that you simply cannot understand what I wrote. Do you agree that it is true that: "18 is the second number (after 12) to be the sum-of-divisors of more than one number, viz. 10 and 17." ...? Imaginatorium (talk) 17:48, 15 August 2024 (UTC)

Huh? Strange commentary you made in your first sentence. Ah, yes I agree with your newly-quoted statement, and they are both note-worthy points to include, since they don't have many solutions, and only have one non-trivial one. Either way of stating it is fine, clearly, though I rather give the numbers that have a SOD of 18 or for any given number x *particularly with a small number of such solutions*Radlrb (talk) 20:41, 15 August 2024 (UTC) (i.e., if it is not clear enough, to list them explicitly). Radlrb (talk) 17:53, 15 August 2024 (UTC)

Once again, your first sentence appears to confirm you do not understand what I am saying. Can you really not see anything odd about saying: "Hey, this number is the SOD of just one number (provided we jiggle with things to omit the other number because it's prime); and Hey, this number is the SOD of two numbers (and only the second such)." Can you explain how 'the largest number of [solutions] so far' can be compatible with *particularly with a small number of such solutions*? And if this is not routine, what is? Imaginatorium (talk) 11:32, 16 August 2024 (UTC)

On further reflection, I have concluded that I was wrong to restore the bit about 18 being the sum-of-divisors of 10. It was synthesis, adding an observation not given in the cited source to make the claim sound more important. XOR'easter (talk) 21:02, 17 August 2024 (UTC)