[QUOTE=Xyzzy;104164]Post something (mathematically) interesting about your forum User ID number.[/QUOTE]

1873 is prime.

1873 = 28[sup]2[/sup]+33[sup]2[/sup]

You can arrange 12 3x3 LEGOs exactly 1873 different ways to build a contiguous structure that is symmetric when rotated by 90 degrees. ([url=http://www.research.att.com/~njas/sequences/A123834]reference[/url])

1667 is prime.
667 is prime.
67 is prime.
7 is prime.
(OK, I lied about one of them!)

It appears in lots of integer sequences, but what do [I]you [/I]think is cool about 1667?

[QUOTE=Flatlander;104350]It appears in lots of integer sequences, but what do [I]you [/I]think is cool about 1667?[/QUOTE]
Almost a beer brand. That's cool :D

cf [url]http://www.k1664.co.uk/[/url]
:victor:

[QUOTE=drew;104345]You can arrange 12 3x3 LEGOs exactly 1873 different ways to build a contiguous structure that is symmetric when rotated by 90 degrees. ([url=http://www.research.att.com/~njas/sequences/A123834]reference[/url])[/QUOTE]
I'm probably missing the point here, but i don't think lego do a 3x3 brick. ( I could be wrong; I've just read that they do do a 1x14 that i've never seen )

There weren't any pictures at the end of that link, unfortunately.

[QUOTE=victor;104268]53.6563^2 = 2878.99852969 != 2879 :no:
[/QUOTE]


I rounded a little :blush:

5!+6!+1! = 29^2

Much more interesting, however, is that 561 is the smallest Carmichael number.

[QUOTE=Richard Cameron;104357]I'm probably missing the point here, but i don't think lego do a 3x3 brick.[/QUOTE]
You're right, that's beside the point.

[quote=Richard Cameron;104357]I'm probably missing the point here, but i don't think lego do a 3x3 brick. ( I could be wrong; I've just read that they do do a 1x14 that i've never seen ).[/quote]
IIRC, the standard height is 3 times the height of the flat bricks, so a 1x3 brick of standard height can be decomposed in 3x3 "elementary" (flat) 1x1 bricks.