a(n) = A192387(n)/2.

Terms

a(0) =0a(1) =1a(2) =2a(3) =16a(4) =48a(5) =256a(6) =928a(7) =4288a(8) =16896a(9) =73728a(10) =301056a(11) =1283072a(12) =5318656a(13) =22446080a(14) =93634560a(15) =393543680a(16) =1646034944a(17) =6906380288a(18) =28918677504a(19) =121248940032a(20) =507934408704