A217492 - OEIS

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A217492

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

1

0, 1, 3, 4, 9, 18, 49, 57, 67, 69, 106, 126, 258, 583, 1221, 1366, 4311, 11361, 12621, 14964, 16017, 22467, 25434, 45094, 51051, 89113

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OFFSET

1,3

COMMENTS

Contains exactly the halved even terms of A217137.

LINKS

Table of n, a(n) for n=1..26.

MATHEMATICA

Select[Range[5000], PrimeQ[9^# + 10] &] (* Vincenzo Librandi, Oct 05 2012 *)

PROG

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

CROSSREFS

Cf. A217137, A217347.

Sequence in context: A103295 A352134 A304257 * A374965 A178784 A192288

Adjacent sequences: A217489 A217490 A217491 * A217493 A217494 A217495

KEYWORD

nonn,more,hard

AUTHOR

Vincenzo Librandi, Oct 05 2012

EXTENSIONS

a(18)-a(26) added from the data at A217137 by Amiram Eldar, Jun 19 2022

STATUS

approved