A385230 Odd multiplicative orders of -4 modulo primes.

1, 3, 7, 9, 5, 13, 15, 25, 9, 7, 17, 37, 13, 43, 45, 49, 19, 67, 23, 73, 39, 79, 87, 93, 97, 11, 51, 105, 19, 115, 127, 65, 135, 139, 71, 37, 153, 163, 165, 169, 175, 177, 61, 189, 95, 193, 199, 101, 205, 207, 213, 107, 219, 235, 17, 83, 23, 85, 265, 89, 91, 277, 279, 141, 59, 75

Offset

1,2

Comments

Odd elements in A380531.

a(n) is the multiplicative order of -4 modulo A385224(n).

Links

Jianing Song, Table of n, a(n) for n = 1..10000

Mathematica

Select[Map[MultiplicativeOrder[-4, #] &, Prime[Range[200]]], OddQ] (* Paolo Xausa, Jun 30 2025 *)

Prog

(PARI) forprime(p=3, 1e4, z=znorder(Mod(-4, p)); if(z%2, print1(z, ", ")))

Crossrefs

Cf. A380531, A385224 (corresponding primes).

Cf. other bases: A139686 (base 2), A385226 (base 3), A385227 (base 4), A385193 (base 5), A385228 (base -2), A385229 (base -3), this sequence (base -4), A385231 (base -5).

Sequence in context: A087655 A016621 A388222 * A342354 A385488 A011271

Adjacent sequences: A385227 A385228 A385229 * A385231 A385232 A385233

Keyword

nonn,easy

Author

Jianing Song, Jun 22 2025

Status

approved