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 A174465 #14 Sep 01 2018 03:54:57
%S A174465 1,1,4,7,19,31,74,122,258,430,835,1378,2557,4162,7382,11932,20471,
%T A174465 32676,54634,86251,141001,220371,353413,546783,863043,1322425,2057525,
%U A174465 3125092,4801297,7230393,10984924,16410474,24679719,36593278,54526145,80272501
%N A174465 G.f.: exp( Sum_{n>=1} A174466(n)*x^n/n ) where A174466(n) = Sum_{d|n} d*sigma(n/d)*tau(d).
%C A174465 Compare to the g.f. of the number of planar partitions of n (A000219):
%C A174465 exp( Sum_{n>=1} sigma_2(n)*x^n/n ) where sigma_2(n) = Sum_{d|n} d*sigma(n/d)*phi(d).
%C A174465 tau(n) = A000005(n) = the number of divisors of n,
%C A174465 and sigma(n) = A000203(n) = sum of divisors of n.
%H A174465 Vaclav Kotesovec, <a href="/A174465/b174465.txt">Table of n, a(n) for n = 0..10000</a>
%F A174465 G.f.: Product_{i>=1, j>=1, k>=1} 1/(1 - x^(i*j*k)). - _Vaclav Kotesovec_, Jan 04 2017
%F A174465 G.f.: Product_{k>=1} 1/(1 - x^k)^tau_3(k), where tau_3() = A007425. - _Ilya Gutkovskiy_, May 22 2018
%t A174465 nmax = 50; CoefficientList[Series[Product[1/(1-x^(i*j*k)), {i, 1, nmax}, {j, 1, nmax/i}, {k, 1, nmax/i/j}], {x, 0, nmax}], x] (* _Vaclav Kotesovec_, Jan 04 2017 *)
%t A174465 nmax = 50; A007425 = Table[Sum[DivisorSigma[0, d], {d, Divisors[n]}], {n, 1, nmax}]; s = 1 - x; Do[s *= Sum[Binomial[A007425[[k]], j]*(-1)^j*x^(j*k), {j, 0, nmax/k}]; s = Expand[s]; s = Take[s, Min[nmax + 1, Exponent[s, x] + 1, Length[s]]];, {k, 2, nmax}]; CoefficientList[Series[1/s, {x, 0, nmax}], x] (* _Vaclav Kotesovec_, Aug 30 2018 *)
%o A174465 (PARI) {a(n)=polcoeff(exp(sum(m=1,n,x^m/m*sumdiv(m,d,d*sigma(m/d)*sigma(d,0)))+x*O(x^n)),n)}
%Y A174465 Cf. A174466, A000203 (sigma), A000005 (tau), A006171, A007425, A280473, A280487.
%K A174465 nonn
%O A174465 0,3
%A A174465 _Paul D. Hanna_, Apr 04 2010