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 A082513 #4 Oct 15 2013 22:31:56
%S A082513 -1,-1,0,-1,1,-1,2,0,1,0,3,-1,4,2,2,1,5,1,6,2,4,4,7,1,6,5,5,3,8,2,9,5,
%T A082513 7,7,7,2,10,8,8,4,11,5,12,8,8,10,13,5,12,9,11,9,14,8,12,8,12,12,15,5,
%U A082513 16,14,12,11,14,10,17,13,15,11,18,8,19,17,15,15,17,13,20,12,17,18,21,11,19,19,19,15,22,12,20,18,20,20,20,12,23,19,19,16
%N A082513 a(n)=A000720(n)-A000005(n).
%t A082513 Table[ -DivisorSigma[0, w]+PrimePi[w], {w, 1, 128}]
%Y A082513 Cf. A000010, A000005, A000720, A073757, A037228, A063070, A045763.
%K A082513 easy,sign
%O A082513 1,7
%A A082513 _Labos Elemer_, Apr 29 2003