A185240 Numbers k such that (35^k + 1)/36 is prime.
11, 13, 79, 127, 503, 617, 709, 857, 1499, 3823, 135623, 280979
Offset: 1
Links
- 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
- Eric Weisstein's World of Mathematics, Repunit
Crossrefs
Cf. A000978 = numbers n such that (2^n + 1)/3 is prime. Cf. A007658, A057171, A057172, A057173, A057175, A001562, A057177, A057178, A057179, A057180, A057181, A057182, A057183, A057184, A057185, A057186, A057187, A057188, A057189, A057190, A057191, A071380, A071381, A071382. Cf. A084741, A084742, A065507, A126659, A126856.
Programs
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Mathematica
Do[ p=Prime[n]; If[ PrimeQ[ (35^p + 1)/36 ], Print[p] ], {n, 1, 9592} ] -
PARI
is(n)=isprime((35^n+1)/36) \\ Charles R Greathouse IV, Feb 17 2017
Extensions
a(11)=135623 found as probable prime and added by Paul Bourdelais, Jul 05 2018
a(12) from Paul Bourdelais, Sep 13 2021
Comments