A242202 Numbers n such that n*9^n - 1 is prime.

10, 58, 264, 1568, 4198, 24500

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*9^n-1)];

Mathematica

Select[Range[2000], PrimeQ[# 9^# - 1] &]

PARI

is(n)=ispseudoprime(n*9^n-1) \\ Charles R Greathouse IV, Jun 06 2017

Extensions

a(5)-a(6) from Harvey's list (see Links).