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 A062950 #6 Dec 15 2017 17:35:16 %S A062950 -1,-1,0,-1,0,0,0,0,0,0,5,0,2,2,6,0,3,2,5,0,0,2,7,5,3,5,9,2,8,6,7,6, %T A062950 15,5,20,3,15,6,21,5,10,7,15,0,0,6,10,7,14,15,15,3,21,15,20,9,0,6,41, %U A062950 8,20,14,35,7,14,14,13,15,12,15,54,20,21,20,41,15,16,14,12,21,0,15,30,10,27,21,39,15,54,13,41,0,54,14,75,10,41,21,42,14 %N A062950 C(H(n)), where C(n) is Chowla's function (A048050) and H(n) is the half-totient function (A023022). %o A062950 (PARI) C(n)=sigma(n)-n-1; H(n)=eulerphi(n)/2; j=[]; for(n=3,150,j=concat(j,C(H(n)))); j %Y A062950 Cf. A048050, A023022. %K A062950 sign %O A062950 3,11 %A A062950 _Jason Earls_, Jul 21 2001