A300408 Primes of the form 19*2^n + 1.

1217, 19457, 1337006139375617

Offset: 1

Author

Martin Renner, Mar 05 2018

Keywords

• nonn
• less

Comments

Next term a(4) = 19*2^366 + 1 > 10^111.

For the corresponding exponents n see A032359.

Links

• Ray Ballinger, Wilfried Keller, List of primes k*2^n + 1 for k < 300.

Crossrefs

Cf. A019434, A032359, A039687, A050527, A050528, A050529, A195745, A050526, A300406, A300407.

Programs

GAP

Filtered(List([1..500],n->19*2^n + 1),IsPrime); # Muniru A Asiru, Mar 06 2018

Maple

a:=(n,k)->`if`(isprime(k*2^n+1), k*2^n+1, NULL):
seq(a(n,19), n=1..366);

PARI

lista(nn) = {for(k=1, nn, if(ispseudoprime(p=19*2^k+1), print1(p, ", ")));} \\ Altug Alkan, Mar 29 2018