Even bisection of A113281: a(n) = A113281(2*n).

Terms

a(0) =1a(1) =3a(2) =11a(3) =51a(4) =255a(5) =1325a(6) =7039a(7) =37951a(8) =206799a(9) =1135969a(10) =6279509a(11) =34889553a(12) =194664283a(13) =1089943229a(14) =6120967411a(15) =34463104999a(16) =194474062663