a(1)=1, a(n) = a(n-1) + n^4 if n odd, a(n) = a(n-1) + n^2 if n is even.

Terms

a(0) =1a(1) =5a(2) =86a(3) =102a(4) =727a(5) =763a(6) =3164a(7) =3228a(8) =9789a(9) =9889a(10) =24530a(11) =24674a(12) =53235a(13) =53431a(14) =104056a(15) =104312a(16) =187833a(17) =188157a(18) =318478a(19) =318878a(20) =513359a(21) =513843a(22) =793684a(23) =794260a(24) =1184885a(25) =1185561a(26) =1717002a(27) =1717786a(28) =2425067a(29) =2425967