a(n) = C(n+5, 5)*(n+3)*(-1)^(n+1)*16/3.

Terms

a(0) =-16a(1) =128a(2) =-560a(3) =1792a(4) =-4704a(5) =10752a(6) =-22176a(7) =42240a(8) =-75504a(9) =128128a(10) =-208208a(11) =326144a(12) =-495040a(13) =731136a(14) =-1054272a(15) =1488384a(16) =-2062032a(17) =2808960a(18) =-3768688a(19) =4987136a(20) =-6517280a(21) =8419840a(22) =-10764000a(23) =13628160a(24) =-17100720a(25) =21280896a(26) =-26279568a(27) =32220160a(28) =-39239552