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 A281591 #10 Apr 15 2017 19:31:34
%S A281591 3,5,6,5,7,6,8,7,8,8,8,8,9,9,9,9,10,10,10,10,10,10,11,11,10,11,12,11,
%T A281591 11,12,11,12,12,12,12,13,12,13,12,13,13,13,13,13,13,13,14,13,14,13,14,
%U A281591 14,14,14,14,14,15,14,15,14,15,14,15,15,15,15,15,15,16
%N A281591 First differences of A281590.
%H A281591 Vaclav Kotesovec, <a href="/A281591/b281591.txt">Table of n, a(n) for n = 1..2611</a>
%t A281591 nmax = 1000; A284896 = Rest[CoefficientList[Series[Product[1/(1 + x^k)^(k^2), {k, 1, nmax}], {x, 0, nmax}], x]]; csign = {1}; Do[If[(A284896[[n]] < 0 && A284896[[n+1]] >= 0) || (A284896[[n]] >= 0 && A284896[[n+1]] < 0), csign = Flatten[{csign, n + 1}]], {n, 1, Length[A284896] - 1}]; Differences[csign]
%Y A281591 Cf. A284896, A281590.
%K A281591 nonn
%O A281591 1,1
%A A281591 _Vaclav Kotesovec_, Apr 14 2017