A057181 Numbers n such that (15^n + 1)/16 is a prime.
3, 7, 29, 1091, 2423, 54449, 67489, 551927, 1841911, 1848811
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
Programs
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Mathematica
Select[Range[3000], PrimeQ[(15^# + 1) / 16] &] (* Vincenzo Librandi, Oct 29 2017 *)
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PARI
isok(n) = (denominator(p=(15^n+1)/16)==1) && isprime(p); \\ Michel Marcus, Oct 29 2017
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Prime95
PRP=1,15,551927,1,0,0,"16"
Extensions
a(6) from Paul Bourdelais, Mar 15 2010
a(7) from Paul Bourdelais, Mar 16 2010
a(8) from Paul Bourdelais, Jul 03 2013
a(9)-a(10) from Paul Bourdelais, Jul 08 2024
Comments