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

Terms

a(0) =0a(1) =1a(2) =4a(3) =9a(4) =64a(5) =25a(6) =576a(7) =49a(8) =4096a(9) =81a(10) =25600a(11) =121a(12) =147456a(13) =169a(14) =802816a(15) =225a(16) =4194304a(17) =289a(18) =21233664a(19) =361a(20) =104857600a(21) =441a(22) =507510784a(23) =529a(24) =2415919104a(25) =625a(26) =11341398016a(27) =729a(28) =52613349376a(29) =841