Third left hand column of triangle A163940.

Terms

a(0) =0a(1) =3a(2) =17a(3) =52a(4) =121a(5) =240a(6) =428a(7) =707a(8) =1102a(9) =1641a(10) =2355a(11) =3278a(12) =4447a(13) =5902a(14) =7686a(15) =9845a(16) =12428a(17) =15487a(18) =19077a(19) =23256a(20) =28085a(21) =33628a(22) =39952a(23) =47127a(24) =55226a(25) =64325a(26) =74503a(27) =85842a(28) =98427a(29) =112346