A237440 Quadruple Hex-primes: let f(n) = A102489(n); then sequence lists primes p such that f(p), f(f(p)). f(f(f(p))) and f(f(f(f(p)))) are also primes.

2, 3, 5, 7, 61, 97, 101, 257, 2531, 4783, 5683, 6317, 8963, 9463, 9497, 11593, 15683, 18757, 23687, 26251, 29611, 31271, 36011, 45497, 45979, 46853, 54869, 73379, 92557, 93761, 104173, 107857, 107981, 121607, 134047, 192091, 196853, 236729, 285599, 310081

Offset

1,1

Comments

The sequence is a subset of sequences A103144, A237438, and A237439.

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Example

Dec61=prime -> Hex61=Dec97=prime -> Hex97=Dec151=prime -> Hex151=Dec337=prime -> Hex337=Dec823=prime.

Mathematica

qhpQ[n_]:=AllTrue[Rest[NestList[FromDigits[IntegerDigits[#], 16]&, n, 4]], PrimeQ]; Select[Prime[Range[27000]], qhpQ] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Mar 13 2016 *)

Prog

(PARI) isok(p)= isprime(p) && isprime(p=hd(p)) && isprime(p=hd(p)) && isprime(p=hd(p)) && isprime(p=hd(p)); \\ Michel Marcus, Feb 09 2014

Crossrefs

Cf. A102489.

Cf. A103144 (Hex-primes), A237438 (Double Hex-primes), A237439 (Triple Hex-primes), A237441 (Quintuple Hex-primes).

Sequence in context: A244597 A237439 A048402 * A237441 A171029 A241723

Adjacent sequences: A237437 A237438 A237439 * A237441 A237442 A237443

Keyword

nonn,base

Author

Andreas Boe, Feb 07 2014

Extensions

More terms from Michel Marcus, Feb 09 2014

Status

approved