A138601 Numbers k such that 2^(2*k-37) - 37 is prime.

24, 30, 66, 74, 390, 1194, 1244, 2166, 2580, 4488, 6380, 9066

Offset

1,1

Comments

a(13) > 90000. - Michael S. Branicky, May 21 2026

Links

Table of n, a(n) for n=1..12.

Example

2^(2*24-37)-37 = 2011, 2^(2*30-37)-37 = 8388571, 2^(2*66-37)-37 = 39614081257132168796771975131, ... .

Mathematica

q=37; For[i=q, i<=q, a={}; Do[x=2^(2*n-i)-i; If[PrimeQ[x], AppendTo[a, n]], {n, 10^3}]; Print["2^(2*n-", i, ")-", i, " ", a]; i=i+2]
Select[Range[5000], PrimeQ[2^(2 # - 37) - 37] &] (* Harvey P. Dale, Dec 03 2021 *)

Prog

(PARI) is(n)=isprime(2^(2*n-37)-37) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Cf. A138577, A138578, A138579, A138580, A138581, A138582.

Cf. A138598, A138599, A138600, A138602, A138603.

Sequence in context: A372991 A333122 A391131 * A135045 A109321 A349689

Adjacent sequences: A138598 A138599 A138600 * A138602 A138603 A138604

Keyword

nonn,more

Author

Vladimir Joseph Stephan Orlovsky, May 13 2008

Extensions

More terms from Harvey P. Dale, Dec 03 2021

Terms 20 and 21 removed and a(11)-a(12) from Michael S. Branicky, May 20 2026

Status

approved