a(n) = 10*binomial(n,5) + 6*binomial(n,4) + binomial(n,3) + binomial(n,2).

Terms

a(0) =0a(1) =0a(2) =1a(3) =4a(4) =16a(5) =60a(6) =185a(7) =476a(8) =1064a(9) =2136a(10) =3945a(11) =6820a(12) =11176a(13) =17524a(14) =26481a(15) =38780a(16) =55280a(17) =76976a(18) =105009a(19) =140676a(20) =185440a(21) =240940a(22) =309001a(23) =391644a(24) =491096a(25) =609800a(26) =750425a(27) =915876a(28) =1109304a(29) =1334116