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A023267 Numbers n such that n remains prime through 2 iterations of function f(x) = 9x + 8. 4
7, 11, 19, 61, 97, 107, 131, 181, 251, 271, 397, 401, 419, 467, 557, 601, 677, 727, 907, 929, 1129, 1297, 1439, 1481, 1609, 1699, 1747, 1901, 1931, 2027, 2029, 2099, 2221, 2267, 2357, 2377, 2557, 2617, 2879, 3001, 3019, 3121, 3259, 3371, 3407, 3457, 3527 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

n, 9*n+8 and 81*n+80 are primes. - Vincenzo Librandi, Aug 04 2010

LINKS

John Cerkan, Table of n, a(n) for n = 1..10000

PROG

(MAGMA) [n: n in [1..100000] | IsPrime(n) and IsPrime(9*n+8) and IsPrime(81*n+80)] // Vincenzo Librandi, Aug 04 2010

CROSSREFS

Subsequence of A023235.

Sequence in context: A162857 A307965 A323109 * A319224 A282037 A050562

Adjacent sequences:  A023264 A023265 A023266 * A023268 A023269 A023270

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved

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Last modified August 17 16:54 EDT 2019. Contains 326059 sequences. (Running on oeis4.)