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 A207137 #8 Sep 07 2013 20:34:34
%S A207137 1,1,2,4,17,171,3171,101741,7181615,1274607729,428568152553,
%T A207137 223160743256395,185627109707405932,320952534083059792786,
%U A207137 1367454166673309618606950,11078799748881429582280609036,137939599816546528357634500253053,2679390013936303204526656964298150849
%N A207137 G.f.: exp( Sum_{n>=1} x^n/n * Sum_{k=0..n} binomial(n^2, k*(n-k))*x^k ).
%C A207137 The logarithmic derivative yields A207138.
%C A207137 Equals the antidiagonal sums of triangle A228900.
%e A207137 G.f.: A(x) = 1 + x + 2*x^2 + 4*x^3 + 17*x^4 + 171*x^5 + 3171*x^6 +...
%e A207137 where the logarithm of the g.f. equals the l.g.f. of A207138:
%e A207137 log(A(x)) = x + 3*x^2/2 + 7*x^3/3 + 51*x^4/4 + 761*x^5/5 + 17913*x^6/6 +...
%o A207137 (PARI) {a(n)=polcoeff(exp(sum(m=1,n,x^m/m*sum(k=0,m,binomial(m^2,k*(m-k))*x^k))+x*O(x^n)),n)}
%o A207137 for(n=0,25,print1(a(n),", "))
%Y A207137 Cf. A207138 (log), A207135, A228900, A206850, A206830, A167006.
%K A207137 nonn
%O A207137 0,3
%A A207137 _Paul D. Hanna_, Feb 15 2012