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 A177399 #2 Mar 30 2012 18:37:21
%S A177399 1,2,10,188,1414,53596,2923652,44668152,651967302,605335444140,
%T A177399 7564881098284,157357140966472,96537385644719004,695895399853879448,
%U A177399 86358988630956719304,1103071610291574716763120
%N A177399 O.g.f.: exp( Sum_{n>=1} (sigma(2n)-sigma(n))^n * x^n/n ).
%C A177399 Here sigma(n) = A000203(n) is the sum of divisors of n.
%C A177399 Compare g.f. to the formula for Jacobi theta_4(x) given by:
%C A177399 . theta_4(x) = exp( Sum_{n>=1} -(sigma(2n)-sigma(n))*x^n/n )
%C A177399 where theta_4(x) = 1 + Sum_{n>=1} 2*(-x)^(n^2).
%e A177399 G.f.: A(x) = 1 + 2*x + 10*x^2 + 188*x^3 + 1414*x^4 + 53596*x^5 +...
%e A177399 log(A(x)) = 2*x + 4^2*x^2/2 + 8^3*x^3/3 + 8^4*x^4/4 + 12^5*x^5/5 +...+ A054785(n)^n*x^n/n +...
%o A177399 (PARI) {a(n)=polcoeff(exp(sum(m=1,n,(sigma(2*m)-sigma(m))^m*x^m/m)+x*O(x^n)),n)}
%Y A177399 Cf. A054785, A000203, A177398, A155200.
%K A177399 nonn
%O A177399 0,2
%A A177399 _Paul D. Hanna_, May 30 2010