Sum over each antidiagonal of A248011.

Terms

a(0) =0a(1) =0a(2) =3a(3) =16a(4) =67a(5) =204a(6) =546a(7) =1268a(8) =2714a(9) =5348a(10) =9965a(11) =17580a(12) =29781a(13) =48520a(14) =76660a(15) =117624a(16) =176196a(17) =257976a(18) =370503a(19) =522456a(20) =725175a(21) =991540a(22) =1337974a(23) =1782924a(24) =2349438a(25) =3063164a(26) =3955601a(27) =5061524a(28) =6423017a(29) =8086224