A242201 Numbers n such that n*8^n - 1 is prime.

1, 2, 7, 12, 25, 44, 219, 252, 507, 1155, 2259, 2972, 4584, 12422, 13905, 75606

Offset: 1

Author

Vincenzo Librandi, May 09 2014

Keywords

• nonn
• more

Links

• Steven Harvey, Generalized Woodall Search

Crossrefs

Cf. similar sequences listed in A242200.

Programs

Magma

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

Mathematica

Select[Range[3000], PrimeQ[# 8^# - 1] &]

PARI

is(n)=ispseudoprime(n*8^n-1) \\ Charles R Greathouse IV, Jun 06 2017

Extensions

a(13)-a(16) from Harvey's list (see Links).