a(n) = n*(n + 1)*(n + 2)*(n + 3)*(n^2 - n + 5)/120.

Terms

a(0) =1a(1) =7a(2) =33a(3) =119a(4) =350a(5) =882a(6) =1974a(7) =4026a(8) =7623a(9) =13585a(10) =23023a(11) =37401a(12) =58604a(13) =89012a(14) =131580a(15) =189924a(16) =268413a(17) =372267a(18) =507661a(19) =681835a(20) =903210a(21) =1181510a(22) =1527890a(23) =1955070a(24) =2477475a(25) =3111381a(26) =3875067a(27) =4788973a(28) =5875864a(29) =7161000