A192764 Numbers k such that 2^(k-1)+2*k-1 is a prime number.

1, 2, 6, 14, 66, 86, 230, 2006, 3876, 3920, 5418, 8820, 11900, 16669, 19446, 28243, 33408, 37919, 40595

Offset: 1

Author

Juri-Stepan Gerasimov, Jul 09 2011

Keywords

• nonn
• more

Comments

a(20) > 10^5 if it exists. - Michael S. Branicky, Aug 26 2024

Crossrefs

Cf. A004051, A163115, A176691, A192436.

Programs

Mathematica

Select[Range[4000], PrimeQ[2^(# - 1) + 2# - 1] &] (* Alonso del Arte, Jul 09 2011 *)

PARI

for(n=1,10^6,if(ispseudoprime(2^(n-1)+2*n-1),print1(n,", ")));

Extensions

a(13)-a(19) from Michael S. Branicky, Jul 14 2023