A Pell Jacobsthal product.

Terms

a(0) =0a(1) =1a(2) =2a(3) =15a(4) =60a(5) =319a(6) =1470a(7) =7267a(8) =34680a(9) =168435a(10) =810898a(11) =3921103a(12) =18918900a(13) =91381991a(14) =441150502a(15) =2130258075a(16) =10285325040a(17) =49663079099a(18) =239791814010