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 A145075 #9 Mar 30 2012 18:37:15
%S A145075 1,4,18,172,1881,25644,411488,7581792,157296141,3630709734,
%T A145075 92225760033,2556393882912,76774488792326,2483261807354874
%N A145075 Coefficient of x^(5^n) in Q(x)^(n+1), where Q(x) = Sum_{k>=0} (x^(5^k) + x^(2*5^k) + x^(3*5^k) + x^(4*5^k)).
%o A145075 (PARI) {a(n,q=5)=local(Q=sum(j=0,n,(x^(q^j)-x^(q*q^j))/(1-x^(q^j)+O(x^(q^n+1)))));polcoeff(Q^(n+1),q^n)}
%Y A145075 Cf. A007178, A145073, A145074, A145076.
%K A145075 more,nonn
%O A145075 0,2
%A A145075 _Paul D. Hanna_, Oct 09 2008
%E A145075 a(7)-a(13) from _Max Alekseyev_, Dec 19 2011