%I #8 Nov 03 2019 12:05:35
%S 1,10,31,988,811,19102,131093,1096792,2420773,95052434,48911887,
%T 4616289884,5904218077,36168951362,534488973899,269764710179504,
%U 17133785963669,34783298901958,652516251742073,2644314567590492
%N Numerator of 1/(2n-1) + 3/(2n-3) + 5/(2n-5) + ...(2n-1)/1.
%e a(1)=1, a(2)=10 as (1/3 + 3/1) = 10/3, a(3)=31 as 1/5 + 3/3 + 5/1 = 31/5.
%o (Rexx)
%o numeric digits 100; do N = 1 to 22; X = 1; do K = 1 to N; X = X*(2*K-1); end K; Y = 0; do K = 1 to N; Y = Y +(2*K-1)*X/(2*N-(2*K-1)); end K; say Y / GCD(X,Y); end; N
%K nonn,frac,easy
%O 1,2
%A _Amarnath Murthy_, May 06 2001
%E Corrected and extended by _Frank Ellermann_