1 if n is a prime power p^k (k >= 0), otherwise 0.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =0a(6) =1a(7) =1a(8) =1a(9) =0a(10) =1a(11) =0a(12) =1a(13) =0a(14) =0a(15) =1a(16) =1a(17) =0a(18) =1a(19) =0a(20) =0a(21) =0a(22) =1a(23) =0a(24) =1a(25) =0a(26) =1a(27) =0a(28) =1a(29) =0