OFFSET
1,2
LINKS
M. A. Alekseyev, J. M. Grau, A. M. Oller-Marcen. Computing solutions to the congruence 1^n + 2^n + ... + n^n == p (mod n). Discrete Applied Mathematics, 2018. doi:10.1016/j.dam.2018.05.022 arXiv:1602.02407 [math.NT]
MATHEMATICA
f[n_] := Mod[Sum[PowerMod[k, n, n], {k, 1, n}] - 19, n];
For[n = 1, n < 40000, n++, If[f[n] == 0, Print[n]]] (* Jean-François Alcover, Sep 06 2018 *)
CROSSREFS
KEYWORD
nonn,fini,full
AUTHOR
N. J. A. Sloane, Dec 29 2016
STATUS
approved