a(n) = binomial(n+3,n)*binomial(n+7,n).

Terms

a(0) =1a(1) =32a(2) =360a(3) =2400a(4) =11550a(5) =44352a(6) =144144a(7) =411840a(8) =1061775a(9) =2516800a(10) =5562128a(11) =11583936a(12) =22926540a(13) =43411200a(14) =79070400a(15) =139163904a(16) =237557133a(17) =394558560a(18) =639331000a(19) =1013012000a(20) =1572701130a(21) =2396496960a(22) =3589794000a(23) =5293080000a(24) =7691506875a(25) =11026544256a(26) =15610063392