Second column of triangle in A182971.

Terms

a(0) =0a(1) =0a(2) =9a(3) =64a(4) =259a(5) =784a(6) =1974a(7) =4368a(8) =8778a(9) =16368a(10) =28743a(11) =48048a(12) =77077a(13) =119392a(14) =179452a(15) =262752a(16) =375972a(17) =527136a(18) =725781a(19) =983136a(20) =1312311a(21) =1728496a(22) =2249170a(23) =2894320a(24) =3686670a(25) =4651920a(26) =5818995a(27) =7220304a(28) =8892009a(29) =10874304