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 A171776 #2 Mar 30 2012 18:37:20
%S A171776 1,1,5,141,25161,25295385,129002055885,3167498196303525,
%T A171776 363195624958803434385,190409085693362565632615985,
%U A171776 449225585595812339036501379506325
%N A171776 E.g.f.: A(x) = exp( Sum_{n>=1} 2^(n(n-1)) * x^n/n ).
%F A171776 a(n) = A155200(n)*n!/2^n and is odd for n>=0.
%e A171776 E.g.f.: A(x) = 1 + x + 5*x^2/2! + 141*x^3/3! + 25161*x^4/4! +...
%e A171776 log(A(x)) = x + 4*x^2/2 + 64*x^3/3 + 4096*x^4/4 + 1048576*x^5/5 +..
%o A171776 (PARI) {a(n)=n!*polcoeff(exp(sum(m=1, n+1, 2^(m*(m-1))*x^m/m)+x*O(x^n)), n)}
%Y A171776 Cf. A155200.
%K A171776 nonn
%O A171776 0,3
%A A171776 _Paul D. Hanna_, Jan 20 2010