A379988 Numbers k such that (27^k + 2^k)/29 is prime.

11, 2297, 2707, 3187

Offset

1,1

Comments

The definition implies that k must be a prime.

a(5) > 10^5.

Links

Table of n, a(n) for n=1..4.

P. 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.

Mathematica

Select[Prime[Range[10000]], PrimeQ[(27^# + 2^#)/29] &]

Crossrefs

Cf. A057187, A057188, A062587, A062589, A127996, A127997, A128344, A204940, A217320, A225807, A228922, A229542, A375161, A375236, A377031, A377856.

Sequence in context: A272617 A301473 A087403 * A085878 A238633 A266815

Adjacent sequences: A379985 A379986 A379987 * A379989 A379990 A379991

Keyword

nonn,hard,more

Author

Robert Price, Jan 07 2025

Status

approved