Numbers n such that f(n) and f(f(n)) are prime, where f(k) = decimal encoding of the prime factorization of k.

A067600

Numbers n such that f(n) and f(f(n)) are prime, where f(k) = decimal encoding of the prime factorization of k.

Terms

    a(0) =3a(1) =20a(2) =69a(3) =171a(4) =174a(5) =267a(6) =333a(7) =360a(8) =372a(9) =448a(10) =537a(11) =665a(12) =666a(13) =776a(14) =820a(15) =824a(16) =855a(17) =873a(18) =1016a(19) =1125a(20) =1330a(21) =1413a(22) =1450a(23) =1532a(24) =1604a(25) =1689a(26) =1796a(27) =1860a(28) =1899a(29) =1959

External references