A305331 Multiplicative order of 5 (mod p^2), where p = prime(n), or 0 if 5 and p are not coprime.

1, 6, 0, 42, 55, 52, 272, 171, 506, 406, 93, 1332, 820, 1806, 2162, 2756, 1711, 1830, 1474, 355, 5256, 3081, 6806, 3916, 9312, 2525, 10506, 11342, 2943, 12656, 5334, 8515, 18632, 9591, 5513, 11325, 24492, 8802, 27722, 29756, 15931, 2715, 3629, 37056, 38612

Offset

1,2

Links

Table of n, a(n) for n=1..45.

Mathematica

Table[If[p==5, 0, MultiplicativeOrder[5, p^2]], {p, Prime@ Range@ 45}] (* Giovanni Resta, May 31 2018 *)

Prog

(PARI) a(n) = my(p=prime(n)); if(p==5, return(0), return(znorder(Mod(5, p^2))))

Crossrefs

Cf. A211241, A305332, A305333.

Sequence in context: A262888 A262894 A262890 * A169769 A357966 A353226

Adjacent sequences: A305328 A305329 A305330 * A305332 A305333 A305334

Keyword

nonn

Author

Felix Fröhlich, May 30 2018

Status

approved