A057185 Numbers n such that (19^n + 1)/20 is a prime.
17, 37, 157, 163, 631, 7351, 26183, 30713, 41201, 77951, 476929
Offset: 1
Keywords
Links
- 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
Programs
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Mathematica
Select[Range[0, 10000], PrimeQ[((19^# + 1) / 20)] &] (* Vincenzo Librandi, Mar 20 2015 *)
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Prime95
PRP=1,19,476929,1,0,0,"20" # Paul Bourdelais, Mar 20 2015
Extensions
26183 from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 05 2008
a(8)-a(9) give probable primes discovered by Paul Bourdelais, Mar 15 2010
a(10) gives a probable prime discovered by Paul Bourdelais, Mar 18 2010
a(11) gives a probable prime discovered by Paul Bourdelais, Mar 20 2015