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A057915
Numbers k such that 2*5^k - 3 is prime.
0
1, 2, 5, 6, 8, 9, 17, 76, 154, 188, 329, 497, 609, 1401, 2320, 3250, 3281, 5489, 6868, 7602, 28666, 30969, 40612, 44705
OFFSET
1,2
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
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
a(23)-a(24) from Michael S. Branicky, Oct 25 2024
STATUS
approved