a(n) = [x^n] Product_{k>=0} (1 + n*x^(2^k)).

Terms

a(0) =1a(1) =1a(2) =2a(3) =9a(4) =4a(5) =25a(6) =36a(7) =343a(8) =8a(9) =81a(10) =100a(11) =1331a(12) =144a(13) =2197a(14) =2744a(15) =50625a(16) =16a(17) =289a(18) =324a(19) =6859a(20) =400a(21) =9261a(22) =10648a(23) =279841a(24) =576a(25) =15625a(26) =17576a(27) =531441a(28) =21952a(29) =707281