A058588 Numbers k such that 5*2^k - 3 is prime.

0, 1, 2, 3, 5, 6, 8, 9, 12, 17, 20, 27, 29, 30, 36, 62, 72, 83, 117, 119, 137, 149, 152, 176, 201, 243, 470, 540, 590, 611, 887, 996, 1118, 1148, 1269, 1431, 2099, 2117, 3822, 5373, 5640, 6677, 8352, 19355, 25937, 27749, 27948, 34877, 40536, 46641, 63891, 66950, 80451

Offset

1,3

Comments

a(49) > 37557. - Jinyuan Wang, Jan 21 2020

a(69) > 1000000. - Jon Grantham, Aug 04 2023

Links

Jon Grantham, Table of n, a(n) for n = 1..68

Jon Grantham and Andrew Granville, Fibonacci primes, primes of the form 2^n-k and beyond, arXiv:2307.07894 [math.NT], 2023.

Mathematica

Do[ If[ PrimeQ[ 5*2^n - 3 ], Print[ n ] ], {n, 0, 10000} ]

Prog

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

Crossrefs

Sequence in context: A030759 A030709 A226806 * A357742 A035399 A354852

Adjacent sequences: A058585 A058586 A058587 * A058589 A058590 A058591

Keyword

nonn

Author

Robert G. Wilson v, Dec 26 2000

Extensions

First term 0 inserted by Georg Fischer, Aug 01 2019

a(44)-a(48) from Jinyuan Wang, Jan 21 2020

a(49)-a(50) from Michael S. Branicky, May 20 2023

a(51) and beyond from Jon Grantham, Jul 30 2023

Status

approved