a(n) = binomial(n+7,7)*binomial(n+12,7).

Terms

a(0) =792a(1) =13728a(2) =123552a(3) =772200a(4) =3775200a(5) =15402816a(6) =54609984a(7) =172931616a(8) =498841200a(9) =1330243200a(10) =3316739712a(11) =7801876368a(12) =17439488352a(13) =37263864000a(14) =76488984000a(15) =151448188320a(16) =290275694280a(17) =540192201120a(18) =978609060000