A237441 Quintuple Hex-primes: let f(n) = A102489(n); then sequence lists primes p such that f(p), f(f(p)), f(f(f(p))), f(f(f(f(p)))) and f(f(f(f(f(p))))) are also primes.

2, 3, 5, 7, 61, 101, 196853, 516151, 548239, 568627, 595039, 603833, 648887, 1996223, 2086907, 2487227, 3322757, 3711343, 4385137, 5226049, 5288929, 5853241, 8792039, 8796187, 8982191, 10203203, 12640297, 12664129, 12845561, 13156267, 13437481, 14342431

Offset: 1

Author

Andreas Boe, Feb 07 2014

Keywords

• nonn
• base

Comments

The sequence is a subset of A103144, A237438, A237439 and A237440

Examples

			Dec61=prime -> Hex61=Dec97=prime -> Hex97=Dec151=prime -> Hex151=Dec337=prime -> Hex337=Dec823=prime -> Hex823=Dec2083=prime.
		

Crossrefs

Cf. A102489

Cf. A103144(Hex-primes), A237438(Double Hex-primes), A237439(Triple Hex-primes), A237440(Quadruple Hex-primes).

Programs

PARI

hd(n) = my(d = digits(n)); sum(i=1, #d, 16^(i-1)*d[#d-i+1]);
isok(p) = isprime(p) && isprime(p=hd(p)) && isprime(p=hd(p)) && isprime(p=hd(p)) && isprime(p=hd(p)) && isprime(p=hd(p)); \\ Michel Marcus, Feb 08 2014

Extensions

More terms from Michel Marcus, Feb 08 2014