a(n) = (A388289(n)^2 - 1)/(3*2^5), for n >= 1.

Terms

a(0) =0a(1) =3a(2) =98a(3) =969a(4) =108878a(5) =312018a(6) =3694603a(7) =10078344a(8) =100468830a(9) =1086820980a(10) =4258790305a(11) =10549105808a(12) =32350651245a(13) =144668863570a(14) =343512402093