A055691 Numbers k such that 8^k == -1 (mod k-1).

2, 6, 14, 66, 186, 378, 546, 1190, 1470, 2406, 4470, 5250, 7086, 18578, 20166, 25806, 42602, 58590, 69006, 85566, 134946, 137346, 170586, 187838, 206646, 262146, 272610, 285390, 289394, 420210, 500570, 538734, 592410, 595686, 602250, 618450

Offset: 1

Author

Robert G. Wilson v, Jun 09 2000

Keywords

• nonn

Programs

Mathematica

Do[If[PowerMod[8, n, n-1]==n-2, Print[n]], {n, 2, 10^7}]