a(n) = binomial(n+7,7)*binomial(n+11,7).

Terms

a(0) =330a(1) =6336a(2) =61776a(3) =411840a(4) =2123550a(5) =9060480a(6) =33372768a(7) =109219968a(8) =324246780a(9) =886828800a(10) =2261413440a(11) =5427392256a(12) =12352970916a(13) =26829982080a(14) =55895796000a(15) =112183843200a(16) =217706770710a(17) =409800980160a(18) =750266946000