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 A138830 #5 Mar 31 2012 07:54:12 %S A138830 2,4,7,9,11,13,15,17,19,21,23,25,27,30,32,34,36,38,40,42,44,46,48,50, %T A138830 52,54,56,58,60,62,64,66,68,70,72,74,76,78,80,82,84,86,88,90,92,94,96, %U A138830 98,100,102,104,106,108,110,112,114,116,118 %N A138830 Bisection of imperfect numbers A132999. %C A138830 The conjectured g.f. (-x^14+x^13-x^3+x^2+2)/(x^2-2*x+1) that a correspondent suggested is wrong and fails after roughly 240 terms [_R. J. Mathar_, Jun 15 2009] %Y A138830 Cf. A000396, A099057, A099058, A132999, A138829. %K A138830 easy,nonn %O A138830 1,1 %A A138830 _Omar E. Pol_, Apr 06 2008