OFFSET
1,3
COMMENTS
Conjecture: For n > 1, a(n) = 0 if and only if n is a term of A088164, i.e., n is a Wolstenholme prime (cf. Mestrovic, 2012, Conjecture 2.10).
LINKS
Seiichi Manyama, Table of n, a(n) for n = 1..1000
R. Mestrovic, A congruence modulo n^3 involving two consecutive sums of powers and its applications, arXiv:1211.4570 [math.NT], 2012.
MAPLE
seq(add(i^(n-2), i=1..n-1) mod n^3, n=1..100);
MATHEMATICA
Table[Mod[Sum[i^(n - 2), {i, n - 1}], n^3], {n, 44}] (* Michael De Vlieger, Apr 02 2017 *)
PROG
(PARI) a(n) = lift(Mod(sum(i=1, n-1, i^(n-2)), n^3))
(PARI) a(n)=my(m=n^3, e=n-2); lift(sum(i=1, n-1, Mod(i, m)^e)) \\ Charles R Greathouse IV, Apr 07 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Felix Fröhlich, Apr 02 2017
STATUS
approved