a(1)=1, a(n)=a(n-1)+n^1 if n odd, a(n)=a(n-1)+ n^3 if n is even.

Terms

a(0) =1a(1) =9a(2) =12a(3) =76a(4) =81a(5) =297a(6) =304a(7) =816a(8) =825a(9) =1825a(10) =1836a(11) =3564a(12) =3577a(13) =6321a(14) =6336a(15) =10432a(16) =10449a(17) =16281a(18) =16300a(19) =24300a(20) =24321a(21) =34969a(22) =34992a(23) =48816a(24) =48841a(25) =66417a(26) =66444a(27) =88396a(28) =88425a(29) =115425