A242198 Numbers k such that k*15^k + 1 is prime.

8, 14, 44, 154, 274, 694, 17426, 59430

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..2500] | IsPrime(n*15^n+1)];

Mathematica

Select[Range[2000], PrimeQ[# 15^# + 1] &]

PARI

is(n)=ispseudoprime(n*15^n+1) \\ Charles R Greathouse IV, Jun 06 2017

Extensions

a(7)-a(8) from Loeh's list (see Links)