A057914 Numbers k such that 2*5^k + 3 is prime.

0, 1, 2, 6, 7, 26, 35, 50, 115, 171, 204, 219, 362, 644, 1959, 4427, 5406, 8030, 10755, 67826

Offset

1,3

Comments

a(20) > 28465. - Jinyuan Wang, Dec 08 2019

a(21) > 10^5. - Tyler NeSmith, Oct 04 2022

Links

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

Mathematica

Do[ If[ PrimeQ[ 2*5^n + 3 ], Print[ n ] ], {n, 0, 2000} ]

Prog

(PARI) is(n)=ispseudoprime(2*5^n+3) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Sequence in context: A220946 A243795 A060112 * A216037 A250547 A366061

Adjacent sequences: A057911 A057912 A057913 * A057915 A057916 A057917

Keyword

nonn,more

Author

Robert G. Wilson v, Nov 16 2000

Extensions

First term 0 inserted by Georg Fischer, Aug 01 2019

a(17)-a(19) from Jinyuan Wang, Dec 08 2019

a(20) from Tyler NeSmith, Oct 04 2022

Status

approved