A215533 Numbers n such that n^s(n) + 1 is a prime, where s(n) is the sum of the digits of n.

1, 2, 4, 10, 20, 100, 110, 152, 220, 242, 736, 790, 800, 916, 1010, 1078, 1106, 1232, 1528, 1636, 1834, 2284, 2330, 2392, 2600, 3100, 3562, 3904, 4000, 4066, 4228, 4444, 4552, 5056, 6082, 6208, 6226, 7810, 8170, 8530, 9520

Offset

1,2

Links

Table of n, a(n) for n=1..41.

Mathematica

t = {}; Do[If[PrimeQ[(n^Total[IntegerDigits[n]]) + 1], AppendTo[t, n]], {n, 10000}]; t
Select[Range[10000], PrimeQ[#^Total[IntegerDigits[#]]+1]&] (* Harvey P. Dale, Aug 26 2019 *)

Crossrefs

Sequence in context: A349430 A129211 A175204 * A128461 A011956 A371358

Adjacent sequences: A215530 A215531 A215532 * A215534 A215535 A215536

Keyword

nonn,base

Author

Vicente Izquierdo Gomez, Aug 15 2012

Status

approved