OFFSET
2,1
COMMENTS
a(n) is 0 for n=8,14,20,... (n=2 mod 6) because, for those n, the polynomial x^n-x+1 has the factor x^2-x+1. Using a result of Selmer, it can be shown that x^n-x+1 is irreducible for all other n. Does a(n) exist for all n>1?
MATHEMATICA
Table[f=FactorList[x^n-x+1]; If[Length[f]>2, k=0, k=1; While[ !PrimeQ[k^n-k+1], k++ ]]; k, {n, 2, 100}]
CROSSREFS
KEYWORD
nonn
AUTHOR
T. D. Noe, Jan 12 2006
STATUS
approved