a(n) = Sum_{k=0..7} binomial(14,k)*binomial(n,k).

Terms

a(0) =1a(1) =15a(2) =120a(3) =680a(4) =3060a(5) =11628a(6) =38760a(7) =116280a(8) =316767a(9) =788161a(10) =1805100a(11) =3840420a(12) =7660250a(13) =14446134a(14) =25947612a(15) =44668692a(16) =74091645a(17) =118941555a(18) =185495056a(19) =281936688a(20) =418766304a(21) =609260960a(22) =869994720a(23) =1221419808a(24) =1688512539a(25) =2301487461a(26) =3096583140a(27) =4116923020