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 A007998 #9 Nov 30 2015 00:20:06 %S A007998 1,2,3,3,4,5,5,7,8,9,9,15,11,17,17,18,18,31,21,33,30,33,30,53,34,48, %T A007998 46,53,43,87,47,73,69,79,66,110,65,100,94,111,80,159,86,135,130,135, %U A007998 108,202,116,181,153,175,133,255,150,212 %N A007998 Number of primitive solutions to x + y + z = 0 (mod n). %C A007998 I can't reconstruct this. Possibly an erroneous version of A003050 or A048259. - _N. J. A. Sloane_ %Y A007998 Cf. A007997. %K A007998 nonn,obsc %O A007998 1,2 %A A007998 _N. J. A. Sloane_