OFFSET
1,1
COMMENTS
An odd prime p is a counterexample of Kurepa's conjecture if and only if B(p-1) = 1 modulo p.
EXAMPLE
a(1)=3 since B(2)=2 has order 2 modulo 3.
a(3)=37, since B(36)=6 modulo 37 has order 4 = 2^2 modulo 37.
MATHEMATICA
Do[p = Prime[k]; m = Mod[BellB[p-1], p]; If[m != 0, f = FactorInteger[MultiplicativeOrder[m, p]]; If[Length[f] == 1 && f[[1, 1]] == 2, Print[p]]], {k, 1, 500}] (* Vaclav Kotesovec, May 06 2022 *)
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Luis H. Gallardo, May 05 2022
STATUS
approved