%I A006523
%S A006523 2,240,725760,12454041600,711374856192000,102181884343418880000,
%T A006523 31022420086661971968000000,17683523987479403909087232000000,
%U A006523 17366635237623772991036388802560000000
%N A006523 Sum ((-1)^(i+1)*binomial(n,i)*2^i*(2*n-1)!,i=1..n) for n odd.
%Y A006523 Sequence in context: A087226 A071967 A024348 this_sequence A055968 A074256 
               A146312
%Y A006523 Adjacent sequences: A006520 A006521 A006522 this_sequence A006524 A006525 
               A006526
%K A006523 nonn
%O A006523 1,1
%A A006523 N. J. A. Sloane (njas(AT)research.att.com).