%I #20 Apr 02 2017 10:36:56
%S 1,2,10,140,5740,700280,255602200,279628806800,917462115110800,
%T 9029662136920493600,266600774592577573540000,
%U 23613897008762965998731960000,6274708327065504088149055143160000
%N a(1)=1, a(n) = 2 * Sum_{k=1..n-1} (3^k-1)/2 * a(k) for n>=2.
%H Michael De Vlieger, <a href="/A156296/b156296.txt">Table of n, a(n) for n = 0..64</a>
%F a(n) = 2*A015502(n+1) for n>1. - _Joe Slater_, Mar 23 2017
%t Table[QPochhammer[-1, 3, n+1]/2^(n+1), {n, 0, 15}] (* _Vaclav Kotesovec_, Mar 24 2017 *)
%K nonn,easy
%O 0,2
%A _Roger L. Bagula_, Feb 07 2009
%E New name from _Joerg Arndt_, Mar 24 2017