%I A073014
%S A073014 1,9,127,2835,93901,4336878,266268402,20961918435,2057633544961,
%T A073014 246291719185578,35300219800649134,5967365133741366446,
%U A073014 1174674087014062487490,266337973265724541242428
%N A073014 (n!/2)*sum(k=1,n,(n+k)!/(k!)^3).
%C A073014 a(n) is odd for n = 1,2,3 and if n is of the form 2^m or 2^m+1 (with 
               m>= 2) (i.e. a(n) is odd if n=1,3,4,5,8,9,16,17,32,33,64,65,128,129,
               256,257...)
%o A073014 (PARI) a(n)=if(n<0,0,(n!/2)*sum(k=1,n,(n+k)!/(k!)^3))
%Y A073014 Sequence in context: A065707 A034301 A092651 this_sequence A046754 A064746 
               A075762
%Y A073014 Adjacent sequences: A073011 A073012 A073013 this_sequence A073015 A073016 
               A073017
%K A073014 easy,nonn
%O A073014 1,2
%A A073014 Benoit Cloitre (benoit7848c(AT)orange.fr), Aug 03 2002