Talk:Narcissistic number
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2006 comment
edit- These examples shouldn't have links, since they are base 3 and 4 numbers but the links are to base 10 numbers and so are meaningless --206.171.6.11 15:12, 8 November 2006 (UTC)
- Some base three Armstrong numbers are: 0,1,2,12,122
- Some base four Armstrong numbers are: 0,1,2,3,313
Open question?
editThe article says:
- However, it is not known if the only base 10 numbers equal to the sum of the cubes of their digits are 1, 153, 370, 371, and 407.
Surely this is untrue? The sum of the cubes of the digits of n cannot exceed 93·log(n). But this quantity is far smaller than n when n is bigger than, say, 106. And a simple brute-force search should take care of all smaller numbers. -- Dominus 21:05, 31 January 2007 (UTC)
In fact, it is untrue. The comment at [1] says essentially the same thing. I have removed the mistaken assertion from the article. -- Dominus 21:12, 31 January 2007 (UTC)
What is biggest such number?
editSince there are a finite number of such numbers, what is the biggest such number?
"Plus perfect" vs "pluperfect"
editHi - I just reverted a well-meant edit, that was seemingly correcting "pluperfect" to "plus perfect". My revert was based solely on primary source publications known to me ... actually, only two primary sources: http://www.geocities.com/~harveyh/narciss.htm and http://www.deimel.org/rec_math/DI_3.htm -- if there are other primary sources using a different term, I'd be glad to reconsider. Until then, I see the term "plusperfect" or "plus perfect" only in secondary or tertiary debates, which are non-original and therefore a possible misnomer. Comments? Thanks, Jens Koeplinger (talk) 04:24, 4 February 2008 (UTC)
4150
editSilly question here, but couldn't it be argued that 04150 is a narcissistic number, and because 04150 = 4150, the latter is also narcissistic? —Preceding unsigned comment added by 65.5.206.147 (talk) 19:52, 6 June 2008 (UTC)
other results from search engine
editthe other results from search engine show that armstrong number is a number which is equal to the sum of CUBE of its digits.
- Only if it has just three digits. Gandalf61 (talk) 12:03, 25 April 2010 (UTC)
88
edit“There are 88 narcissistic numbers”. Is it because it was mathematically demonstrated that there can be no more such numbers, or are there 88 known narcissistic numbers until we find the 89th? Calimo (talk) 08:32, 12 January 2012 (UTC)
- It has been proved that there can only be 88 narcissistic numbers in base 10. The Mathworld page says "a total of 88 narcissistic numbers exist in base 10, as proved by D. Winter in 1985". Gandalf61 (talk) 14:39, 12 January 2012 (UTC)
- I couldn't find the proof, is there a link to it? I'd like to see how it was proved that there are only 88 narcissistic numbers by D.Winter. --Graphene15 (talk) 08:54, 13 November 2015 (UTC)
0^0?
editIn my opinion it might not be adequate to affirm 0 is a narcissistic number, as 0^0 is undefined. — Preceding unsigned comment added by 186.114.45.138 (talk) 02:42, 20 January 2012 (UTC)
- Actually, it's almost always useful to define 0^0=1, and I would claim that the consensus among mathematicians is "it's 1 unless you have a strong reason for it not to be 1 in your specific situation". See, e.g., https://www.math.hmc.edu/funfacts/ffiles/10005.3-5.shtml Misof (talk) 10:05, 1 August 2014 (UTC)
"Formula"
editSomebody recently added a link to a "formula" (quotes added by me) to the article. I just removed it because it is useless. The formula in question (see the FORMULA section at http://oeis.org/A005188) is simply the definition of the number: take each digit, raise it to the correct power, sum it all up, check whether you got the original. It is just written in a (rather uselessly complicated) way with a lot of floor()s and powers of ten. This does not add any new value to the article, and such a "formula" should not be added back to the article in the future. Misof (talk) 09:49, 1 August 2014 (UTC)
External links modified (January 2018)
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External links modified (February 2018)
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