a(n) = binomial(n+6,6)*binomial(n+9,6).

Terms

a(0) =84a(1) =1470a(2) =12936a(3) =77616a(4) =360360a(5) =1387386a(6) =4624620a(7) =13741728a(8) =37165128a(9) =92912820a(10) =217273056a(11) =479693760a(12) =1007356896a(13) =2024399916a(14) =3912705720a(15) =7303717344a(16) =13213962300a(17) =23241027810a(18) =39841761960a(19) =66720654000a(20) =109363854600a(21) =175763337750a(22) =277386503940a(23) =430459323840