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 A104097 #6 Aug 12 2019 16:36:22 %S A104097 1,1,3,1,45,5,315,189,2025,4725,467775,1485,42567525,212837625, %T A104097 91216125,42567525,97692469875,516891375,9280784638125,236238154425, %U A104097 43752270436875,714620417135625,147926426347074375,53123043290625,48076088562799171875 %N A104097 Denominators of coefficients in expansion of x^-2*(1-exp(-2*x))^2. %H A104097 Robert Israel, <a href="/A104097/b104097.txt">Table of n, a(n) for n = 0..504</a> %p A104097 S:= series(x^(-2)*(1-exp(-2*x))^2, x, 32): %p A104097 seq(denom(coeff(S, x, j)), j=0..31); # Robert Israel, Aug 12 2019 %Y A104097 See A104042 for more information. %K A104097 nonn,frac %O A104097 0,3 %A A104097 _N. J. A. Sloane_, Apr 18 2005