a(1)=1, a(n) = a(n-1) + n^5 if n odd, a(n) = a(n-1) + n^2 if n is even.

Terms

a(0) =1a(1) =5a(2) =248a(3) =264a(4) =3389a(5) =3425a(6) =20232a(7) =20296a(8) =79345a(9) =79445a(10) =240496a(11) =240640a(12) =611933a(13) =612129a(14) =1371504a(15) =1371760a(16) =2791617a(17) =2791941a(18) =5268040a(19) =5268440a(20) =9352541a(21) =9353025a(22) =15789368a(23) =15789944a(24) =25555569a(25) =25556245a(26) =39905152a(27) =39905936a(28) =60417085