A057915 Numbers k such that 2*5^k - 3 is prime.

1, 2, 5, 6, 8, 9, 17, 76, 154, 188, 329, 497, 609, 1401, 2320, 3250, 3281, 5489, 6868, 7602, 28666, 30969

Offset

1,2

Links

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

Mathematica

Do[ If[ PrimeQ[ 2*5^n - 3 ], Print[ n ] ], {n, 1, 2000} ]

Prog

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

Crossrefs

Cf. A057914 (2*5^k + 3 is prime).

Sequence in context: A102611 A323112 A176114 * A154329 A176590 A253061

Adjacent sequences: A057912 A057913 A057914 * A057916 A057917 A057918

Keyword

nonn,more

Author

Robert G. Wilson v, Nov 16 2000

Extensions

a(18)-a(20) from Jinyuan Wang, Dec 14 2019

a(21)-a(22) from Michael S. Branicky, Mar 18 2024

Status

approved