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 A156262 #4 Jun 02 2025 01:21:09 %S A156262 1,1,2,3,3,3,4,4,5,5,5,6,7,7,8,8,8,9,10,10,11,12,12,12,13,13,14,15,15, %T A156262 16,17,17,17,18,18,19,20,20,20,21,21,21,22,22,22,23,24,24,25,25,26,27, %U A156262 27,27,28,29,29,30,30,30,31,31,32,32,32,33,33,34,35,35,36,37,37,37,38 %N A156262 a(n)=n/2-(1/2)*sum(k=1,n,A000002(A078649(k)+2)-A000002(A078649(k))). %C A156262 A000002(A078649(n))=A000002(A078649(n)+1) %K A156262 nonn %O A156262 1,3 %A A156262 _Benoit Cloitre_, Feb 07 2009