a(n) = n^4 + 2*n^3 + 4*n^2 + 3*n + 1 = ((n+1)^5+n^5) / (2*n+1).

Terms

a(0) =1a(1) =11a(2) =55a(3) =181a(4) =461a(5) =991a(6) =1891a(7) =3305a(8) =5401a(9) =8371a(10) =12431a(11) =17821a(12) =24805a(13) =33671a(14) =44731a(15) =58321a(16) =74801a(17) =94555a(18) =117991a(19) =145541a(20) =177661a(21) =214831a(22) =257555a(23) =306361a(24) =361801a(25) =424451a(26) =494911a(27) =573805a(28) =661781a(29) =759511