A121166 Integers m that divide A120492(m) = 1 + Sum_{k=1..m} prime(k)^(m-1).

1, 2, 3, 4, 5, 6, 7, 9, 10, 11, 12, 13, 17, 19, 22, 23, 29, 31, 37, 41, 43, 45, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251

Offset

1,2

Comments

Sequence includes all primes and 1, 4, 6, 9, 10, 12, 22, 45, 400, 417, 561, 620, ...

Links

Table of n, a(n) for n=1..62.

Mathematica

Do[f=1 + Sum[ Prime[k]^(n-1), {k, 1, n}]; If[IntegerQ[f/n], Print[n]], {n, 1, 500}]
Module[{nn=500, prs}, prs=Prime[Range[nn]]; Select[Range[nn], Divisible[ Total[Take[prs, #]^(#-1)]+1, #]&]] (* Harvey P. Dale, May 02 2012 *)

Crossrefs

Cf. A120492.

Sequence in context: A331119 A366169 A283970 * A249017 A214879 A187226

Adjacent sequences: A121163 A121164 A121165 * A121167 A121168 A121169

Keyword

nonn

Author

Alexander Adamchuk, Aug 14 2006

Status

approved