OFFSET
1,1
COMMENTS
LINKS
J. M. Grau, A. M. Oller-Marcén, About the congruence sum_{k=1}^n k^f(n) == 0 (mod n), arXiv:1304.2678 [math.NT], 2013.
MATHEMATICA
fa=FactorInteger; Carlitz[k_, n_] := Mod[n-Sum[If[IntegerQ[k/(fa[n][[i, 1]]-1)], n/fa[n][[i, 1]], 0], {i, 1, Length[fa[n]]}], n]; supercar[k_, n_] := If[k == 1 || Mod[k, 2] == 0 || Mod[n, 4] > 0, Carlitz[k, n], Mod[Carlitz[k, n] - n/2, n]]; Table[Print[Length@Select[Range[10^n], supercar[#-1, #] == 0 &]], {n, 1, 7}]
CROSSREFS
KEYWORD
nonn,more,hard
AUTHOR
José María Grau Ribas, Sep 20 2013
STATUS
approved