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A248350 Numbers n such that 10^n - 123456789 is prime. 4
9, 10, 13, 19, 26, 68, 73, 115, 190, 195, 232, 549, 742, 1502, 2239, 2618, 5143, 8081, 9442, 31402, 77919, 93790, 99434, 120841 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(26) > 200000. - Robert Price, Jun 06 2020

LINKS

Table of n, a(n) for n=1..24.

PROG

(PARI) for(n=1, 10^4, if(ispseudoprime(10^n - 123456789), print1(n, ", ")))

CROSSREFS

Cf. A248349, A248351, A248352, A050289.

Sequence in context: A249723 A050593 A189834 * A247512 A110095 A169870

Adjacent sequences:  A248347 A248348 A248349 * A248351 A248352 A248353

KEYWORD

nonn,hard,more

AUTHOR

Derek Orr, Oct 05 2014

EXTENSIONS

a(21)-a(25) from Robert Price, Feb 26 2020

STATUS

approved

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Last modified September 18 10:31 EDT 2020. Contains 337166 sequences. (Running on oeis4.)