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 A224680 #7 Apr 14 2013 21:00:30
%S A224680 1,5,49,1117,57181,7086833,2109733585,1508630963069,2591308566579217,
%T A224680 10691434112980070315,105957942450483004330197,
%U A224680 2522387398320711543274084153,144235039901139444727535460625985,19811186631607253937472121882634566325
%N A224680 a(n) = A224678(n^2).
%C A224680 A224678 is the logarithmic derivative of A023361, where A023361(n) = number of compositions of n into positive triangular numbers.
%F A224680 Logarithmic derivative of A224681.
%e A224680 L.g.f.: L(x) = x + 5*x^2/2 + 49*x^3/3 + 1117*x^4/4 + 57181*x^5/5 + 7086833*x^6/6 +...
%e A224680 where
%e A224680 exp(L(x)) = 1 + x + 3*x^2 + 19*x^3 + 300*x^4 + 11768*x^5 + 1193594*x^6 +...+ A224681(n)*x^n +...
%o A224680 (PARI) {a(n)=n^2*polcoeff(-log(1-sum(r=1, 2*n+1, x^(r*(r+1)/2)+x*O(x^(n^2)))), n^2)}
%o A224680 for(n=1, 20, print1(a(n), ", "))
%Y A224680 Cf. A224681, A224678, A224607.
%K A224680 nonn
%O A224680 1,2
%A A224680 _Paul D. Hanna_, Apr 14 2013