A152080 Composite numbers c for which A000695(c) is prime.

55, 77, 87, 91, 115, 117, 121, 171, 185, 203, 213, 253, 299, 327, 329, 369, 405, 415, 425, 471, 475, 477, 481, 493, 501, 539, 583, 625, 637, 665, 675, 687, 721, 755, 789, 803, 805, 815, 817, 833, 835, 841, 855, 861, 913, 935, 955, 973, 979, 981

Offset: 1

Author

Vladimir Shevelev, Nov 23 2008

Keywords

• nonn

Crossrefs

Cf. A000695, A077718, A152021, A152022, A152023, A152078, A152079.

Programs

Mathematica

f[n_] := FromDigits[IntegerDigits[n, 2], 4]; Select[Range[1000], CompositeQ[#] && PrimeQ[f[#]] &] (* Amiram Eldar, Dec 13 2018 *)

PARI

a000695(n) = fromdigits(binary(n), 4);
lista(nn) = forcomposite(n=1, nn, if (isprime(a000695(n)), print1(n, ", "))); \\ Michel Marcus, Dec 13 2018

Extensions

More terms derived from b000695.txt by Michel Marcus, Jun 02 2013