A242178 Numbers k such that k*8^k + 1 is prime.

5, 17, 23, 1911, 20855, 35945, 42816

Offset: 1

Author

Vincenzo Librandi, May 08 2014

Keywords

• nonn
• more

Links

• G. Loeh, Generalized Cullen primes

Crossrefs

Cf. similar sequences listed in A242176.

Programs

Magma

[n: n in [0..2000] | IsPrime(n*8^n+1)];

Mathematica

Select[Range[2000], PrimeQ[# 8^# + 1] &]

PARI

is(n)=ispseudoprime(n*8^n+1) \\ Charles R Greathouse IV, May 22 2017

Extensions

a(5)-a(7) from Loeh's list (see Links) - Bruno Berselli, May 08 2014