G.f.: (21+104*x+103*x^2+23*x^3+x^4)/(1-x)^5.

Terms

a(0) =21a(1) =209a(2) =938a(3) =2833a(4) =6771a(5) =13881a(6) =25544a(7) =43393a(8) =69313a(9) =105441a(10) =154166a(11) =218129a(12) =300223a(13) =403593a(14) =531636a(15) =688001a(16) =876589a(17) =1101553a(18) =1367298a(19) =1678481a(20) =2040011a(21) =2457049a(22) =2935008a(23) =3479553a(24) =4096601a(25) =4792321a(26) =5573134a(27) =6445713a(28) =7416983