A217493 - OEIS

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A217493

Numbers k such that 9^k - 10 is prime.

1

2, 3, 4, 9, 11, 18, 19, 27, 28, 46, 50, 53, 80, 155, 203, 280, 451, 4963, 6167, 9687, 10083, 31450

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OFFSET

1,1

COMMENTS

Contains exactly the halved even terms of A217347.

LINKS

Table of n, a(n) for n=1..22.

MATHEMATICA

Select[Range[5000], PrimeQ[9^# - 10] &]

PROG

(PARI) is(n)=ispseudoprime(9^n-10) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Cf. A217137, A217347.

Sequence in context: A093514 A215810 A080231 * A368349 A125774 A062410

Adjacent sequences: A217490 A217491 A217492 * A217494 A217495 A217496

KEYWORD

nonn,more

AUTHOR

Vincenzo Librandi, Oct 05 2012

EXTENSIONS

a(19)-a(22) added from the data at A217347 by Amiram Eldar, Jun 19 2022

STATUS

approved