A102545 - OEIS

A102545

Numbers k such that k999999 is prime.

2, 4, 16, 19, 20, 23, 29, 40, 43, 50, 59, 62, 71, 83, 89, 107, 115, 116, 122, 134, 145, 155, 157, 160, 167, 184, 197, 218, 250, 251, 262, 268, 278, 284, 289, 292, 298, 311, 314, 335, 344, 346, 347, 349, 353, 355, 361, 362, 379, 389, 398, 400, 401, 425, 431, 437, 439, 452, 457, 470, 475, 485, 491

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..63.

EXAMPLE

If k=2, then k999999 = 2999999 (prime).

If k=43, then k999999 = 43999999 (prime).

If k=89, then k999999 = 89999999 (prime).

PROG

(Magma) [ n: n in [1..700] | IsPrime(Seqint([9, 9, 9, 9, 9, 9] cat Intseq(n))) ]; // Vincenzo Librandi, Feb 04 2011

CROSSREFS