A248350 Numbers n such that 10^n - 123456789 is prime.

9, 10, 13, 19, 26, 68, 73, 115, 190, 195, 232, 549, 742, 1502, 2239, 2618, 5143, 8081, 9442, 31402, 77919, 93790, 99434, 120841

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 A061445

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