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 A170910 #12 Jan 05 2021 02:40:56
%S A170910 -1,1,1,3,1,13,1,27,8,91,1,1213,1,505,1919,2955,1,24557,1,1136313,
%T A170910 34943,12277,1,65978519,624,57331,58528,195948483,1,1052424027703,1,
%U A170910 77010795,7085759,1179631,37497599,7047825380633,1,5242861,89281919,355723139681937
%N A170910 Write exp(-x) = Product_{n>=1} (1 + g_n * x^n); a(n) = numerator(g_n).
%H A170910 H. Gingold, H. W. Gould, and Michael E. Mays, <a href="https://www.researchgate.net/publication/268023169_Power_product_expansions">Power Product Expansions</a>, Utilitas Mathematica 34 (1988), 143-161.
%H A170910 G. Helms, <a href="http://go.helms-net.de/math/musings/dreamofasequence.pdf">A dream of a (number-) sequence</a>
%e A170910 -1, 1/2, 1/3, 3/8, 1/5, 13/72, 1/7, 27/128, 8/81, 91/800, 1/11, ...
%p A170910 L:=100; t1:=exp(-x); t0:=series(t1,x,L): g:=[]; M:=40; t2:=t0:
%p A170910 for n from 1 to M do t3:=coeff(t2,x,n); t2:=series(t2/(1+t3*x^n),x,L); g:=[op(g),t3]; od: g;
%Y A170910 Cf. A170911 (denominators).
%K A170910 sign,frac
%O A170910 1,4
%A A170910 _N. J. A. Sloane_, Jan 30 2010