A059676 Numbers n such that n*5^n - 1 is prime.

8, 14, 42, 384, 564, 4256, 6368, 21132, 27180, 96584, 349656, 545082

Offset: 1

Author

Robert G. Wilson v, Feb 05 2001

Keywords

• nonn

Links

• Steven Harvey, Generalized Woodall Search

Programs

Mathematica

Do[ If[ PrimeQ[ n*5^n - 1 ], Print[ n ]], {n, 1, 4000} ]

PARI

is(n)=ispseudoprime(n*5^n-1) \\ Charles R Greathouse IV, May 22 2017

Extensions

More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 05 2008

a(11)-a(12) from Harvey link by Ray Chandler, Apr 10 2016