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

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

Offset: 1

Author

Jeppe Stig Nielsen, Apr 12 2016

Keywords

• nonn
• hard
• more

Comments

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

Examples

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

Crossrefs

Cf. A191568, A210340.

Programs

Mathematica

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

PARI

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