a(n) = Sum_{i=0..2n} (-1)^i * T(i,2n-i), array T as in A048149.

Terms

a(0) =1a(1) =8a(2) =17a(3) =38a(4) =63a(5) =102a(6) =121a(7) =170a(8) =217a(9) =276a(10) =359a(11) =422a(12) =473a(13) =562a(14) =643a(15) =776a(16) =861a(17) =966a(18) =1041a(19) =1176a(20) =1303a(21) =1468a(22) =1569a(23) =1712a(24) =1825a(25) =2056a(26) =2225a(27) =2358a(28) =2565a(29) =2722