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 A225549 #13 May 13 2013 01:20:37
%S A225549 2,4,8,16,24,40,68,103,162,236,344,453,612,790,994,1229,1432,1782,
%T A225549 2134,2517,2968,3460,3974,4543,5160,5822,6546,7347,8184,9080,10058,
%U A225549 11075,12166,13316,14536,15837,17202,18654,20156,21765,23450,25212,27074,29001,31032,33158,35370,37679,40070,42578
%N A225549 a(n) is the number of terms in the expansion of (x-y)*(x^4-y^4)*(x^9-y^9)*...*(x^(n^2)-y^(n^2)).
%C A225549 In the definition one can take y=1. Thus the sequence becomes the number of terms in the polynomial of the product{k=1..n} (1-x^(k^2)).
%t A225549 a[n_] := Length@ ExpandAll@ Product[(1 - x^(k^2)), {k, n}]; Array[f, 40]
%o A225549 (PARI) a(n)=my(P=prod(k=1,n,1-'x^k^2)); sum(i=0, poldegree(P), polcoeff(P,i)!=0) \\ _Charles R Greathouse IV_, May 10 2013
%Y A225549 Cf. A000124, A086781, A086795, A086796, A086817.
%K A225549 nonn
%O A225549 1,1
%A A225549 Yuval Dekel (dekelyuval(AT)hotmail.com) and _Robert G. Wilson v_, May 10 2013