A055694 Numbers k such that 11^k == -1 (mod k-1).

2, 3, 5, 7, 13, 62, 75, 378, 637, 2295, 10933, 24255, 31125, 50787, 53685, 55575, 176565, 193242, 243165, 290675, 415215, 579397, 728035, 728742, 741015, 760410, 1281423, 1447515, 1664205, 1975974, 4020030, 4794075, 5778525, 7189014

Offset: 1

Author

Robert G. Wilson v, Jun 09 2000

Keywords

• nonn

Programs

Mathematica

Do[If[PowerMod[11, n, n-1]==n-2, Print[n]], {n, 2, 10^7}]