A288491 Numbers k such that k^k*prime(k) - 1 is prime.

2, 6, 40, 56, 954

Offset: 1

Author

Vincenzo Librandi, Jun 10 2017

Keywords

• nonn
• more

Comments

a(6) > 22000. - Giovanni Resta, Jun 12 2017

a(6) > 40000. - Michael S. Branicky, Jan 05 2025

Examples

			a(1) = 2 because 3*2^2-1 = 11 a prime.
a(2) = 6 because 13*6^6-1 = 606527 a prime.
		

Crossrefs

Cf. A086173.

Programs

Magma

[n: n in [1..1000] | IsPrime(NthPrime(n)*n^n-1)];

Mathematica

Select[Range[1000], PrimeQ[Prime[#] #^# - 1] &]