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 A105587 #8 Dec 24 2015 02:45:29
%S A105587 1,2,3,4,1,6,7,8,2,3,11,12,4,14,15,16,5,18,6,20,7,22,23,24,8,9,27,10,
%T A105587 11,30,31,32,12,34,35,36,13,38,39,40,14,42,43,44,15,16,47,48,17,18,19,
%U A105587 52,20,54,21,56,22,58,59,60,23,62,63,24,25,66,67,68,26,70,71,72,27,74,75
%N A105587 Row sums of a Möbius-binomial triangle.
%C A105587 a(n) = n unless n is nonsquarefree, in which case a(n) = rank of n as a nonsquarefree number. Row sums of A105586.
%F A105587 a(n) = Sum_{k=0..n} binomial(abs(mu(n)), abs(mu(k))).
%e A105587 a(4) = 1 since 4 is the first nonsquarefree number;
%e A105587 a(8) = 2 since 8 is the second nonsquarefree number.
%K A105587 easy,nonn
%O A105587 0,2
%A A105587 _Paul Barry_, Apr 14 2005