A193993 Number of zeros in the period of Fibonacci 4-step sequence A000078 mod n.

1, 3, 9, 5, 72, 27, 49, 8, 12, 216, 11, 24, 7, 147, 36, 10, 336, 36, 361, 188, 231, 8, 529, 39, 80, 21, 21, 126, 11, 108, 1986, 14, 51, 1008, 636, 31, 34, 1083, 36, 152, 11, 693, 3786, 8, 24, 1587, 2209, 51, 56, 56, 1440, 19, 5832, 63, 33, 203, 1653, 9, 3481

Offset: 1

Author

T. D. Noe, Aug 18 2011

Keywords

• nonn

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..200

Crossrefs

Cf. A106295 (period of Lucas 4-step sequence).

Programs

Mathematica

n = 4; Table[a = Join[{1}, Table[0, {n - 1}]]; a = Mod[a, i]; a0 = a; k = 0; zeros = 0; While[k++; s = Mod[Plus @@ a, i]; a = RotateLeft[a]; If[s == 0, zeros++]; a[[n]] = s; a != a0]; zeros, {i, 100}]