A382370 Numbers k such that (k - 1)^(k + 1) - k is prime.

3, 4, 5, 7, 10, 11, 21, 46, 59, 839, 21920

Offset

1,1

Comments

The corresponding primes are 13, 239, 4091, 1679609, 31381059599, 999999999989, 41943039999999999999999999979, ...

Links

Table of n, a(n) for n=1..11.

Mathematica

Select[Range[1000], PrimeQ[(#-1)^(#+1)-#] &] (* Stefano Spezia, Mar 30 2025 *)

Prog

(Magma) [k: k in [2..500] | IsPrime((k-1)^(k+1)-k)];

Crossrefs

Cf. A238378, A240532.

Sequence in context: A048342 A159560 A288427 * A030502 A201025 A288451

Adjacent sequences: A382367 A382368 A382369 * A382371 A382372 A382373

Keyword

nonn,more

Author

Juri-Stepan Gerasimov, Mar 23 2025

Extensions

a(11) from Michael S. Branicky, Mar 25 2025

Status

approved