a(n) = Sum_{k=0..n-2} A205497(n, k) * (k mod 2).

Terms

a(0) =0a(1) =0a(2) =0a(3) =1a(4) =3a(5) =8a(6) =28a(7) =136a(8) =715a(9) =3968a(10) =24928a(11) =176896a(12) =1358611a(13) =11184128a(14) =99463620a(15) =951878656a(16) =9704336283a(17) =104932671488