A228919 Numbers n such that 1^(n+1) + 2^(n+1) + ... + n^(n+1) == 0 (mod n).

1, 4, 5, 7, 8, 11, 12, 13, 16, 17, 19, 20, 23, 24, 25, 28, 29, 31, 32, 36, 37, 40, 41, 43, 44, 47, 48, 49, 52, 53, 56, 59, 60, 61, 64, 65, 67, 68, 71, 72, 73, 76, 79, 80, 83, 84, 85, 88, 89, 91, 92, 96, 97, 100, 101, 103, 104, 107, 108, 109, 112, 113, 116

Offset: 1

Author

José María Grau Ribas, Sep 08 2013

Keywords

• nonn

Links

• Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A191677, A121706.

Programs

Mathematica

f[n_] := Mod[Sum[PowerMod[i, n + 1, n], {i, 1, n}], n]; Select[Range[1000], f[#] == 0 &]

PARI

is(n)=my(m=n+1);sum(k=1,n,Mod(k,n)^m)==0 \\ Charles R Greathouse IV, Nov 20 2013