A123383 Numbers k such that 10*(11*10^k-1) + 3 is prime or PRP.

1, 2, 6, 14, 42, 44, 47, 50, 118, 119, 178, 223, 367, 438, 872, 1378, 2076, 2352, 4195, 5090, 15905, 17454

Offset

1,2

Comments

a(16)-a(19) were computed with PFGW.exe.

Links

Table of n, a(n) for n=1..22.

Prog

(PARI) g(n, m=3) = for(x=1, n, y=10*(11*10^x-1)+m; if(ispseudoprime(y), print1(x", ")))

Crossrefs

Sequence in context: A009423 A008325 A004066 * A281707 A225172 A212197

Adjacent sequences: A123380 A123381 A123382 * A123384 A123385 A123386

Keyword

nonn,more

Author

Cino Hilliard, Oct 13 2006

Extensions

a(20)-a(22) from Michael S. Branicky, Apr 08 2024

Status

approved