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numbers!

Sweet!

The mathematician's numerology: What's special about this number? (link from b_v_borgia)

A few gems:
93 = 333 in base 5.
111 is the smallest possible magic constant of a 3 x 3 magic square of distinct primes.
145 = 1! + 4! + 5!
197 is a Keith number.
226 is the first number he doesn't have anything for.
384 = 8!!
666 is a palindromic triangular number.
668 is the number of legal pawn moves in chess.

Comments

( 8 comments — Leave a comment )
ethernight
Mar. 8th, 2005 12:35 am (UTC)
curious
"2020 is a curious number."

What does that mean?
jnanacandra
Mar. 8th, 2005 12:44 am (UTC)
Re: curious
Huh. Looks like he forgot to put in the definition link.

I don't know, and the only definition I've found online (a number containing all ten digits) obviously doesn't apply to this. 'Tis indeed - er, curious.
blk
Mar. 8th, 2005 02:00 am (UTC)
Re: curious
The only other reasonable definition I found was this one, and that doesn't seem to apply either. Curiouser and curiouser...

Also, what does "8!!" mean?
meerkat299
Mar. 8th, 2005 02:37 am (UTC)
Re: curious
according to
http://mathworld.wolfram.com/DoubleFactorial.html

8!! ≠ (8!)! as I was originally assuming.

for positive, even integers, it is
n!! = n×(n-2)×(n-4)×...×6×4×2

for positive, odd integers, it is
n!! = n×(n-2)×(n-4)×...×5×3×1

Thus 8!! = 8×6×4×2 = 384
lapidus_93
Mar. 8th, 2005 01:04 am (UTC)
Thanks for the information, (especially about 93 and 666) and for the link.
earhart
Mar. 8th, 2005 10:28 pm (UTC)
My favorite's still 1729 -- the smallest number which is the sum of two cubes, two different ways. (Google "Ramanujan" for a good story about it...)
mrlogic
Mar. 9th, 2005 10:55 am (UTC)
I really, really, really, really like this page.

I'm clearly a little bit odd.
jnanacandra
Mar. 9th, 2005 07:49 pm (UTC)
No more odd than the rest of us, then ;)
( 8 comments — Leave a comment )

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