a(n) = binomial(n+5, 5)*binomial(n+8, 5).

Terms

a(0) =56a(1) =756a(2) =5292a(3) =25872a(4) =99792a(5) =324324a(6) =924924a(7) =2378376a(8) =5621616a(9) =12388376a(10) =25729704a(11) =50791104a(12) =95938752a(13) =174350232a(14) =306211752a(15) =521694096a(16) =864913896a(17) =1399125420a(18) =2213431220a(19) =3431347920a(20) =5221616400a(21) =7811703900a(22) =11504509380a(23) =16698853080a(24) =23914406880a(25) =33821804016