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A094963 Numbers k such that 2^k - 3*k is prime. 1
5, 7, 19, 23, 87, 107, 255, 1539, 2387, 4457, 5623, 15761, 22735, 27241 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(15) > 28500. - Jinyuan Wang, Feb 03 2020

LINKS

Table of n, a(n) for n=1..14.

MATHEMATICA

Do[ If[ PrimeQ[2^n - 3n], Print[n]], {n, 1, 15000, 2}]

PROG

(PARI) is(k) = ispseudoprime(2^k-3*k); \\ Jinyuan Wang, Feb 03 2020

CROSSREFS

Cf. A093988 (2^k + 3*k is prime).

Sequence in context: A058079 A076787 A332763 * A255490 A045446 A106074

Adjacent sequences:  A094960 A094961 A094962 * A094964 A094965 A094966

KEYWORD

nonn,more

AUTHOR

Robert G. Wilson v, May 26 2004

EXTENSIONS

a(12)-a(14) from Jinyuan Wang, Feb 03 2020

STATUS

approved

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Last modified July 24 03:29 EDT 2021. Contains 346273 sequences. (Running on oeis4.)