A003566 Least number m such that 10^m == +- 1 mod (10n + 1).

1, 6, 15, 5, 16, 30, 35, 9, 3, 2, 3, 11, 65, 46, 75, 33, 18, 90, 95, 33, 15, 48, 6, 15, 25, 28, 5, 14, 96, 42, 155, 53, 55, 30, 6, 171, 78, 42, 176, 100, 8, 70, 215, 42, 10, 230, 78, 6, 245, 166, 24, 26, 58, 270, 252, 16, 285, 246, 98, 150, 69, 66, 315, 16, 30

Offset

1,2

Links

Alois P. Heinz, Table of n, a(n) for n = 1..10000 (first 1000 terms from Harvey P. Dale)

Mathematica

lnm[n_]:=Module[{m=1}, While[!MemberQ[{1, 10n}, PowerMod[10, m, 10n+1]], m++]; m]; Array[lnm, 60] (* Harvey P. Dale, Feb 12 2022 *)

Crossrefs

Sequence in context: A115408 A327602 A105052 * A349083 A205149 A289722

Adjacent sequences: A003563 A003564 A003565 * A003567 A003568 A003569

Keyword

nonn

Author

N. J. A. Sloane

Status

approved