This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A145682 #3 May 01 2013 21:05:52 %S A145682 2,8,32,113,382,833,1822,3713,7582 %N A145682 The value of the sum shown in the display appears to 2, 8, 32 - sqrt(2), 113, 382, 833, 1822, 3713, 7582, ... for n = 1, ..., 9. %C A145682 This is an unusual sequence mentioned on the Math Fun Mailing list. It does not quite fit the format of regular OEIS entries, but is too interesting to be forgotten. - _N. J. A. Sloane_, Mar 29 2009 %C A145682 The definition arises from the Fourier series for the Snowflake curve. %C A145682 .................................................................. %C A145682 .............................. inf ............................... %C A145682 .............................. ==== ............ m ............... %C A145682 ............................ k \ ....... %pi (k 2..- 5) ..... n .. %C A145682 ....................... (- 1).. > .. tan(--------------) (- 1) ... %C A145682 ............. inf ............ / ............ n + m .............. %C A145682 ............. ==== ........... ==== ........ 2 ................... %C A145682 ..... 5 m - 1 \ .............. n = 1 ............................. %C A145682 .. 3 2 ....... > ...... --------------------------------------- .. %C A145682 ............. / .................................... m ........... %C A145682 ............. ==== .......... m ... 3 ... 10 %pi (k 2 .- 5) ...... %C A145682 ............. k = - inf . (k 2..- 5)..csc(-----------------) ..... %C A145682 ................................................ 2 m ............. %C A145682 ............................................... 2 ................ %C A145682 .. ------------------------------------------------------------ .. %C A145682 ........................... 3 ... 5 %pi .......................... %C A145682 ........................ %pi..csc(-----) ......................... %C A145682 ................................... m ............................ %C A145682 .................................. 2 ............................. %K A145682 nonn %O A145682 1,1 %A A145682 _Bill Gosper_, Apr 12 2005