Column 0 of triangle A115080.

Terms

a(0) =1a(1) =1a(2) =3a(3) =11a(4) =50a(5) =257a(6) =1467a(7) =9081a(8) =60272a(9) =424514a(10) =3151226a(11) =24510411a(12) =198870388a(13) =1676878231a(14) =14648843341a(15) =132228263355