C(n+9, 9)*(n+5)*(-1)^(n+1)*256/5.

Terms

a(0) =-256a(1) =3072a(2) =-19712a(3) =90112a(4) =-329472a(5) =1025024a(6) =-2818816a(7) =7028736a(8) =-16180736a(9) =34850816a(10) =-70946304a(11) =137592832a(12) =-255836672a(13) =458422272a(14) =-794962432a(15) =1338884096a(16) =-2196606720a(17) =3519493120a(18) =-5519205120a(19) =8487198720a(20) =-12819206400a(21) =19045678080a(22) =-27869287680