%I #17 Jun 06 2021 10:56:10
%S 1,2,6,12,60,20,140,280,2520,2520,27720,27720,360360,360360,72072,
%T 144144,2450448,2450448,46558512,232792560,232792560,232792560,
%U 5354228880,5354228880,26771144400,26771144400,80313433200,80313433200,2329089562800,2329089562800
%N Denominators of s(i) = s(i-1) - (1/i)*sign(s(i-1)) with s(1) = 1.
%C Numerators are given in A203810. The first 14 terms coincide with those of A002805.
%H Hugo Pfoertner, <a href="/A203811/b203811.txt">Table of n, a(n) for n = 1..200</a>
%e See A203810.
%t nxt[{n_,a_}]:={n+1,a-1/(n+1) Sign[a]}; NestList[nxt,{1,1},30][[All,2]]//Denominator (* _Harvey P. Dale_, Jun 06 2021 *)
%Y Cf. A002805, A203810 (numerators), A203812.
%K nonn,frac
%O 1,2
%A _Hugo Pfoertner_ and _Rainer Rosenthal_, Jan 06 2012