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 A307497 #16 Apr 12 2019 09:07:33
%S A307497 1,-1,5,-32,294,-3527,51589,-894706,17978610,-410803143,10517824035,
%T A307497 -298204099693,9273022031794,-313755862498513,11474175971184267,
%U A307497 -450960476552715192,18954545423649435646,-848383466771831169101,40285210722052785437974
%N A307497 Expansion of Product_{k>=1} (1+x^k)^((-1)^k*k^k).
%C A307497 This sequence is obtained from the generalized Euler transform in A266964 by taking f(n) = (-1)^(n+1) * n^n, g(n) = -1.
%H A307497 Seiichi Manyama, <a href="/A307497/b307497.txt">Table of n, a(n) for n = 0..386</a>
%F A307497 a(n) ~ (-1)^n * n^n * (1 + exp(-1)/n + (exp(-1)/2 + 5*exp(-2))/n^2). - _Vaclav Kotesovec_, Apr 12 2019
%t A307497 nmax=20; CoefficientList[Series[Product[(1+x^k)^((-1)^k*k^k), {k, 1, nmax}], {x, 0, nmax}], x] (* _Vaclav Kotesovec_, Apr 12 2019 *)
%o A307497 (PARI) N=20; x='x+O('x^N); Vec(prod(k=1, N, (1+x^k)^((-1)^k*k^k)))
%Y A307497 Cf. A083365, A261053, A266964, A284474, A307462.
%K A307497 sign
%O A307497 0,3
%A A307497 _Seiichi Manyama_, Apr 10 2019