Row 2 of array in A226513.

Terms

a(0) =1a(1) =3a(2) =15a(3) =99a(4) =807a(5) =7803a(6) =87135a(7) =1102419a(8) =15575127a(9) =242943723a(10) =4145495055a(11) =76797289539