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 A143968 #12 Mar 24 2023 02:49:54 %S A143968 1,2,4,48,384,1920,46080,645120,5160960,185794560,530841600, %T A143968 40874803200,280284364800,51011754393600,714164561510400, %U A143968 42849873690624000,1371195958099968000,302731575164928000,1678343852714360832000,100120983364435968000,1275541328062914232320000 %N A143968 Denominators of numbers with g.f. exp(1-(1-x)^(1/2)). %H A143968 Robert Israel, <a href="/A143968/b143968.txt">Table of n, a(n) for n = 0..406</a> %e A143968 1, 1/2, 1/4, 7/48, 37/384, 133/1920, 2431/46080, 27007/645120, 176761/5160960, ... %p A143968 S:= series(exp(1-(1-x)^(1/2)),x,21): %p A143968 seq(denom(coeff(S,x,i)),i=0..20); # _Robert Israel_, Mar 23 2023 %t A143968 CoefficientList[Series[Exp[1-Sqrt[1-x]],{x,0,20}],x]//Denominator (* _Harvey P. Dale_, Sep 13 2019 *) %Y A143968 Cf. A143991 (numerators), A001515. %K A143968 nonn,frac %O A143968 0,2 %A A143968 _N. J. A. Sloane_, Dec 02 2008