G.f.: (21+98*x+91*x^2+21*x^3+x^4)/(1-x)^5.

Terms

a(0) =21a(1) =203a(2) =896a(3) =2681a(4) =6371a(5) =13011a(6) =23878a(7) =40481a(8) =64561a(9) =98091a(10) =143276a(11) =202553a(12) =278591a(13) =374291a(14) =492786a(15) =637441a(16) =811853a(17) =1019851a(18) =1265496a(19) =1553081a(20) =1887131a(21) =2272403a(22) =2713886a(23) =3216801a(24) =3786601a(25) =4428971a(26) =5149828a(27) =5955321a(28) =6851831