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 A307675 #20 Jun 02 2019 04:36:11
%S A307675 1,1,1,5,-4,19,-27,61,-89,156,-230,383,-597,981,-1549,2493,-3943,6301,
%T A307675 -10012,16020,-25626,41174,-66193,106639,-171829,277083,-446858,
%U A307675 721033,-1163798,1879329,-3035767,4905405,-7928249,12816369,-20721187,33505745
%N A307675 L.g.f.: log(Product_{k>=1} 1/(1 - x^k/(1 + x))) = Sum_{k>=1} a(k)*x^k/k.
%F A307675 Product {k>=1} 1/(1 - x^k/(1 + x)) = exp(Sum_{k>=1} a(k)*x^k/k).
%e A307675 L.g.f.: L(x) = x/1 + x^2/2 + x^3/3 + 5*x^4/4 - 4*x^5/5 + 19*x^6/6 - 27*x^7/7 + 61*x^8/8 - ... .
%e A307675 exp(L(x)) = 1 + x + x^2 + x^3 + 2*x^4 + x^5 + 4*x^6 + 8*x^8 + ... + A307626(n)*x^n + ... .
%o A307675 (PARI) N=66; x='x+O('x^N); Vec(x*deriv(log(1/prod(k=1, N, 1-x^k/(1+x)))))
%o A307675 (PARI) N=66; x='x+O('x^N); Vec(x*deriv(sum(k=1, N, x^k*sumdiv(k, d, 1/(d*(1+x)^d)))))
%Y A307675 Cf. A307601, A307626, A307674.
%K A307675 sign
%O A307675 1,4
%A A307675 _Seiichi Manyama_, Apr 21 2019