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 A262008 #7 Oct 01 2015 12:41:23 %S A262008 1,2,14,202,16858,6746346,11466918526,80444425726274, %T A262008 2306004013900856642,268654794950929597256002, %U A262008 126765597355485476411443388062,241678070949320865028012988979962410,1858395916568294857820278937430319959202010,57560683587057503330693629888859064500206488317834 %N A262008 G.f.: exp( Sum_{n>=1} x^n/n * Sum_{d|n} 2^(d^2) * n^2/d^2 ). %C A262008 a(n) == 2 (mod 4) for n>0. %e A262008 G.f.: A(x) = 1 + 2*x + 14*x^2 + 202*x^3 + 16858*x^4 + 6746346*x^5 +... %e A262008 The logarithm of the g.f. begins: %e A262008 log(A(x)) = 2*x + 24*x^2/2 + 530*x^3/3 + 65632*x^4/4 + 33554482*x^5/5 + 68719479000*x^6/6 + 562949953421410*x^7/7 + 18446744073709814144*x^8/8 +...+ A262009(n)*x^n/n +... %e A262008 where %e A262008 A262009(n) = Sum_{d|n} 2^(d^2) * n^2/d^2. %o A262008 (PARI) {a(n) = polcoeff( exp(sum(m=1,n,x^m/m * sumdiv(m,d, 2^(d^2) * m^2/d^2))+x*O(x^n)),n)} %o A262008 for(n=0,20,print1(a(n),", ")) %Y A262008 Cf. A262009 (log). %K A262008 nonn %O A262008 0,2 %A A262008 _Paul D. Hanna_, Oct 01 2015