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 A115861 #5 Mar 31 2012 13:21:10 %S A115861 0,0,0,0,0,0,1,0,0,0,1,0,1,1,0,0,0,0,1,0,1,1,2,0,1,1,1,1,2,0,2,0,0,0, %T A115861 1,0,1,1,1,0,1,1,1,1,0,2,2,0,1,1,0,1,1,1,4,1,1,2,3,0,3,2,3,0,0,0,1,0, %U A115861 1,1,2,0,1,1,2,1,2,1,3,0,1,1,2,1,1,1,2,1,2,0,4,2,2,2,2,0,1,1,4,1,2,0 %N A115861 Number of distinct m's < n, such that there exists nonzero solutions to a cross-domain congruence m*i = n X i. %H A115861 <a href="/index/Con#CongruCrossDomain">Index entries for sequences defined by congruent products between domains N and GF(2)[X]</a> %Y A115861 a(2n) = a(n). Cf. A115859, A115869, A115871. %K A115861 nonn %O A115861 1,23 %A A115861 _Antti Karttunen_, Feb 07 2006