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A199165 Numbers n such that (6^n-11)/5 is prime. 1
2, 3, 4, 5, 14, 19, 21, 50, 53, 136, 146, 1255, 1448, 1839, 2053, 2496, 4060, 5041, 8410, 14090, 14940, 19759, 29871, 44836, 78175, 114398, 120946, 137845, 461108, 727496 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..30.

Henri & Renaud Lifchitz, PRP Records.

EXAMPLE

a(4) = 5  because  (6^5-11)/5 = 1553  is prime.

MATHEMATICA

lst={}; Do[If[PrimeQ[(6^n-11)/5], Print[n]; AppendTo[lst, n]], {n, 10^6}]; lst

PROG

(PARI) is(n)=ispseudoprime((6^n-11)/5) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Cf. A004062, A165210, A198725.

Sequence in context: A098552 A245447 A037340 * A202423 A171593 A227535

Adjacent sequences:  A199162 A199163 A199164 * A199166 A199167 A199168

KEYWORD

nonn,more

AUTHOR

Gilbert Mozzo, Nov 03 2011

EXTENSIONS

a(23)-a(28) are probable primes discovered by Paul Bourdelais, Nov 15 2011

a(23)-a(28) independently confirmed as probable primes using Mathematica PrimeQ function by Gilbert Mozzo, Nov 21 2011

a(29) corresponds to a probable prime discovered by Paul Bourdelais, Apr 25 2019

a(30) corresponds to a probable prime discovered by Paul Bourdelais, Aug 12 2019

STATUS

approved

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Last modified February 19 16:24 EST 2020. Contains 332045 sequences. (Running on oeis4.)