%I #23 Mar 04 2023 08:57:57
%S 1,4,108,442368,51200000,52428800000,43177371238400000,
%T 60766747818779941065981952,23542283154891408151173909109014528,
%U 60268244876522004867005207319077191680000000000
%N Let d(1)=1 and d(n) = d(n-1)*n^(2n-2)*(2n-1)^(3-2n). Then a(n)=numerator(d(n)).
%e 1, 4/3, 108/125, 442368/2100875, 51200000/2977309629, 52428800000/118890080527911, ...
%t d[1] = 1; d[n_] := d[n] = d[n - 1]*n^(2 n - 2)*(2 n - 1)^(3 - 2 n); a[n_] := Numerator[d[n]]; Array[a, 10] (* _Amiram Eldar_, Mar 04 2023 *)
%Y Cf. A114877 (denominator).
%K easy,frac,nonn
%O 1,2
%A _T. D. Noe_, Jan 03 2006
%E Edited by _Michel Marcus_, Mar 04 2023