A175289 Pisano period of A002605 modulo n.

1, 1, 3, 1, 24, 3, 48, 1, 9, 24, 10, 3, 12, 48, 24, 1, 144, 9, 180, 24, 48, 10, 22, 3, 120, 12, 27, 48, 840, 24, 320, 1, 30, 144, 48, 9, 36, 180, 12, 24, 280, 48, 308, 10, 72, 22, 46, 3, 336, 120, 144, 12, 936, 27, 120, 48, 180, 840, 29, 24, 60, 320, 144, 1, 24, 30, 1122, 144

Offset

1,3

Comments

a(79)=6240. [John W. Layman, Aug 10 2010]

Links

Michael De Vlieger, Table of n, a(n) for n = 1..200

Example

Reading 0, 1, 2, 6, 16, 44, 120, 328, 896, 2448,.. modulo 12 gives 0, 1, 2, 6, 4, 8, 0, 4, 8, 0, 4, 8 ,.. with period length a(n=12)= 3.

Mathematica

a={1}; For[n=2, n<=80, n++, {x={{0, 1}}; t={1, 1}; While[ !MemberQ[x, t], {xl = x[[ -1]]; AppendTo[x, t]; t={Mod[2*(t[[1]]+xl[[1]]), n], Mod[2*(t[[2]] + xl[[2]]), n]}; }]; p = Flatten[Position[x, t]][[1]]; AppendTo[a, Length[x] - p+1]; }]; Print[a]; (* John W. Layman, Aug 10 2010 *)

Crossrefs

Cf. A001175, A046738, A175181, A175182, A175183, A175184, A175185, A175286.

Sequence in context: A270220 A281377 A138654 * A072271 A363818 A309397

Adjacent sequences: A175286 A175287 A175288 * A175290 A175291 A175292

Keyword

nonn

Author

R. J. Mathar, Mar 24 2010

Extensions

Terms beyond a(28)=48 from John W. Layman, Aug 10 2010

Status

approved