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

Terms

a(0) =1a(1) =5a(2) =8a(3) =24a(4) =29a(5) =65a(6) =72a(7) =136a(8) =145a(9) =245a(10) =256a(11) =400a(12) =413a(13) =609a(14) =624a(15) =880a(16) =897a(17) =1221a(18) =1240a(19) =1640a(20) =1661a(21) =2145a(22) =2168a(23) =2744a(24) =2769a(25) =3445a(26) =3472a(27) =4256a(28) =4285a(29) =5185