a(n) = Pell(n)*Pell(2*n)/2.

Terms

a(0) =0a(1) =1a(2) =12a(3) =175a(4) =2448a(5) =34481a(6) =485100a(7) =6826079a(8) =96049728a(9) =1351523425a(10) =19017374892a(11) =267594778639