A057180 Numbers k such that (14^k + 1)/15 is a prime.

7, 53, 503, 1229, 22637, 1091401, 1385203, 1522841

Offset

1,1

Links

Table of n, a(n) for n=1..8.

Paul Bourdelais, A Generalized Repunit Conjecture

J. Brillhart et al., Factorizations of b^n +- 1, Contemporary Mathematics, Vol. 22, Amer. Math. Soc., Providence, RI, 3rd edition, 2002.

H. Dubner and T. Granlund, Primes of the Form (b^n+1)/(b+1), J. Integer Sequences, 3 (2000), #P00.2.7.

H. Lifchitz, Mersenne and Fermat primes field

Prog

(Prime95) PRP=1, 14, 1091401, 1, 0, 0, "15"

Crossrefs

Sequence in context: A142981 A350252 A120272 * A137612 A092802 A062207

Adjacent sequences: A057177 A057178 A057179 * A057181 A057182 A057183

Keyword

nonn,more,changed

Author

N. J. A. Sloane, Sep 15 2000

Extensions

a(5) from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 05 2008

a(6) from Paul Bourdelais, Mar 10 2014

a(7) from Paul Bourdelais, Feb 08 2022

a(8) from Paul Bourdelais, Feb 18 2025

Status

approved