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 A225958 #7 Jul 24 2013 19:50:11
%S A225958 1,2,10,44,134,468,1524,4584,13862,40566,114880,321052,879092,2360156,
%T A225958 6248864,16297384,41902454,106437600,267149022,662979572,1628437160,
%U A225958 3960377672,9541519732,22786066280,53958062564,126750346970,295476011176,683776368416,1571299804688
%N A225958 O.g.f.: exp( Sum_{n>=1} (sigma(2*n^3) - sigma(n^3)) * x^n/n ).
%C A225958 Compare to the Jacobi theta_3 function:
%C A225958 1 + 2*Sum_{n>=1} x^(n^2) = exp( Sum_{n>=1} -(sigma(2*n) - sigma(n))*(-x)^n/n ).
%C A225958 Here sigma(n) = A000203(n), the sum of the divisors of n.
%F A225958 O.g.f.: exp( Sum_{n>=1} A054785(n^3)*x^n/n ).
%F A225958 Logarithmic derivative equals A225959.
%e A225958 O.g.f.: A(x) = 1 + 2*x + 10*x^2 + 44*x^3 + 134*x^4 + 468*x^5 + 1524*x^6 +...
%e A225958 where
%e A225958 log(A(x)) = 2*x + 8*x^2/2 + 26*x^3/3 + 32*x^4/4 + 62*x^5/5 + 104*x^6/6 + 114*x^7/7 + 128*x^8/8 + 242*x^9/9 + 248*x^10/10 + 266*x^11/11 +...+ A054785(n^3)*x^n/n +...
%o A225958 (PARI) {a(n)=polcoeff(exp(sum(m=1, n, (sigma(2*m^3)-sigma(m^3))*x^m/m)+x^2*O(x^n)), n)}
%o A225958 for(n=0, 50, print1(a(n), ", "))
%Y A225958 Cf. A225957, A225959, A054785, A000203; variants: A195584, A215603, A225925, A224902.
%K A225958 nonn
%O A225958 0,2
%A A225958 _Paul D. Hanna_, May 21 2013