A271718 Numbers n such that n*(n+1)^n - 1 is prime.

2, 3, 7, 14, 43, 81, 943, 1621

Offset

1,1

Comments

The corresponding primes are a subset of the generalized Woodall primes (A210340).

Links

Table of n, a(n) for n=1..8.

Example

14 is a member because 14*15^14 - 1 = 408700964355468749 is a prime number.

Mathematica

Select[Range[10^3], PrimeQ[# (# + 1)^# - 1] &] (* Michael De Vlieger, Apr 12 2016 *)

Prog

(PARI) for(n=1, 10^10, ispseudoprime(n*(n+1)^n-1)&&print1(n, ", "))

Crossrefs

Cf. A191568, A210340.

Sequence in context: A113182 A165433 A238728 * A222626 A006627 A077161

Adjacent sequences: A271715 A271716 A271717 * A271719 A271720 A271721

Keyword

nonn,hard,more

Author

Jeppe Stig Nielsen, Apr 12 2016

Status

approved