A122166 Numbers n such that 1 + Sum k^k (k=1..n) is prime.

1, 52, 124, 431

Offset

1,2

Comments

Primes of the form A001923[n] = Sum k^k (k=1..n) are given in A073826[n] and their indices are given in A073825[n] = {2,5,6,10,30,...}.

Links

Table of n, a(n) for n=1..4.

Mathematica

s=1; Do[s=s+k^k; If[PrimeQ[s], Print[{k, s}]], {k, 1, 500}]

Crossrefs

Cf. A073825, A001923.

Sequence in context: A327147 A346898 A120534 * A205221 A044303 A044684

Adjacent sequences: A122163 A122164 A122165 * A122167 A122168 A122169

Keyword

nonn

Author

Alexander Adamchuk, Aug 23 2006

Status

approved