A057464 Numbers k such that 10*13^k + 1 is prime.

0, 1, 4, 7, 8, 26, 33, 64, 116, 201, 1278, 1927, 2549, 4054, 5379, 5704, 6639, 13785, 18918, 19085

Offset

1,3

Comments

a(18) > 10^4. - Jinyuan Wang, Jan 31 2020

Links

Table of n, a(n) for n=1..20.

Mathematica

Do[ If[ PrimeQ[ 10*13^n + 1 ], Print[ n ] ], {n, 0, 1000} ]
Select[Range[0, 4000], PrimeQ[(10*13^# + 1)] &] (* Vincenzo Librandi, Sep 28 2012 *)

Prog

(PARI) is(n)=ispseudoprime(10*13^n+1) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Sequence in context: A225430 A295325 A239290 * A344781 A160629 A093105

Adjacent sequences: A057461 A057462 A057463 * A057465 A057466 A057467

Keyword

nonn,more

Author

Robert G. Wilson v, Sep 08 2000

Extensions

a(11)-a(13) from Vincenzo Librandi, Sep 28 2012

a(14)-a(17) from Jinyuan Wang, Jan 31 2020

a(18) from Michael S. Branicky, May 02 2023

a(19)-a(20) from Michael S. Branicky, Oct 30 2024

Status

approved