Greatest squarefree number not exceeding n-th prime power which is not prime.

Terms

a(0) =1a(1) =3a(2) =7a(3) =7a(4) =15a(5) =23a(6) =26a(7) =31a(8) =47a(9) =62a(10) =79a(11) =119a(12) =123a(13) =127a(14) =167a(15) =241a(16) =255a(17) =287a(18) =341a(19) =359a(20) =511a(21) =527a(22) =623a(23) =727a(24) =839a(25) =959a(26) =1023a(27) =1330a(28) =1367a(29) =1679