Number of odd terms in f^n, where f = 1/x^2+1/x+1+x+x^2+1/y^2+1/y+y+y^2.

Terms

a(0) =1a(1) =9a(2) =9a(3) =37a(4) =9a(5) =65a(6) =37a(7) =157a(8) =9a(9) =81a(10) =65a(11) =237a(12) =37a(13) =293a(14) =157a(15) =713a(16) =9a(17) =81a(18) =81a(19) =333a(20) =65a(21) =473a(22) =237a(23) =1077a(24) =37a(25) =333a(26) =293a(27) =1129a(28) =157a(29) =1285