a(n) = (n+6)*(n+1)*(n^2 + 7*n + 16)/4.

Terms

a(0) =0a(1) =24a(2) =84a(3) =204a(4) =414a(5) =750a(6) =1254a(7) =1974a(8) =2964a(9) =4284a(10) =6000a(11) =8184a(12) =10914a(13) =14274a(14) =18354a(15) =23250a(16) =29064a(17) =35904a(18) =43884a(19) =53124a(20) =63750a(21) =75894a(22) =89694a(23) =105294a(24) =122844a(25) =142500a(26) =164424a(27) =188784a(28) =215754a(29) =245514