cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-8 of 8 results.

A385192 Primes p such that multiplicative order of 5 modulo p is odd.

Original entry on oeis.org

2, 11, 19, 31, 59, 71, 79, 101, 109, 131, 139, 149, 151, 179, 181, 191, 199, 211, 239, 251, 269, 271, 311, 331, 359, 379, 389, 401, 409, 419, 431, 439, 461, 479, 491, 499, 541, 569, 571, 599, 619, 631, 659, 691, 719, 739, 751, 811, 829, 839, 859, 911, 919, 941, 971, 991
Offset: 1

Views

Author

Jianing Song, Jun 20 2025

Keywords

Comments

The multiplicative order of 5 modulo a(n) is A385193(n).
Contained in primes congruent to 1 or 4 modulo 5 (primes p such that 5 is a quadratic residue modulo p, A045468), and contains primes congruent to 11 or 19 modulo 20 (A122869).
Conjecture: this sequence has density 1/3 among the primes.

Examples

			101 is a term since 5^25 == 1 (mod 101).

Links

Crossrefs

Subsequence of A040105, which (without the terms 2 and 5) is itself a subsequence of A045468.
Contains A122869 as a proper subsequence.
Cf. A385193 (the actual multiplicative orders).
Cf. other bases: A014663 (base 2), A385220 (base 3), A385221 (base 4), this sequence (base 5), A163183 (base -2), A385223 (base -3), A385224 (base -4), A385225 (base -5).

Programs

  • Mathematica
    Select[Prime[Range[200]], OddQ[MultiplicativeOrder[5, #]] &] (* Paolo Xausa, Jun 28 2025 *)
  • PARI
    isA385192(p) = isprime(p) && (p!=5) && znorder(Mod(5,p))%2

A139686 Odd multiplicative orders of 2 modulo primes.

Original entry on oeis.org

3, 11, 5, 23, 35, 9, 39, 11, 51, 7, 15, 83, 95, 99, 37, 29, 119, 131, 135, 155, 21, 179, 183, 191, 43, 73, 231, 239, 243, 251, 299, 25, 303, 45, 323, 359, 121, 371, 375, 411, 419, 431, 55, 443, 91, 153, 117, 483, 491, 495, 515, 519, 531, 543, 29, 575, 611, 615, 639
Offset: 1

Views

Author

Max Alekseyev, Apr 29 2008

Keywords

Comments

Subsequence of A014664, consisting of odd elements.

Links

Crossrefs

Cf. A014664, A014663 (corresponding primes).
Cf. other bases: this sequence (base 2), A385226 (base 3), A385227 (base 4), A385193 (base 5), A385228 (base -2), A385229 (base -3), A385230 (base -4), A385231 (base -5).

Programs

  • Mathematica
    p = Select[Range[1000], PrimeQ]; Select[MultiplicativeOrder[2, #] & /@ p, OddQ] (* Amiram Eldar, Jul 30 2020 *)
  • PARI
    forprime(p=3,10^5,z=znorder(Mod(2,p));if(z%2,print1(z,", ")))

Formula

a(n) = multiplicative order of 2 modulo A014663(n).

A385226 Odd multiplicative orders of 3 modulo primes.

Original entry on oeis.org

1, 5, 3, 11, 23, 29, 35, 41, 53, 27, 65, 83, 89, 45, 95, 113, 57, 119, 125, 131, 69, 155, 39, 173, 179, 191, 209, 105, 43, 27, 221, 233, 239, 49, 251, 135, 281, 293, 299, 75, 323, 329, 31, 177, 359, 183, 371, 9, 413, 207, 419, 431, 443, 455, 473, 485, 491
Offset: 1

Views

Author

Jianing Song, Jun 22 2025

Keywords

Comments

a(n) is the multiplicative order of 3 modulo A385220(n).
Odd elements in A062117.

Links

Crossrefs

Cf. A062117, A385220 (corresponding primes).
Cf. other bases: A139686 (base 2), this sequence (base 3), A385227 (base 4), A385193 (base 5), A385228 (base -2), A385229 (base -3), A385230 (base -4), A385231 (base -5).

Programs

  • Mathematica
    Select[Map[MultiplicativeOrder[3, #] &, Prime[Range[200]]], OddQ] (* Paolo Xausa, Jun 28 2025 *)
  • PARI
    forprime(p=2, 1e4, if(p!=3, z=znorder(Mod(3, p)); if(z%2, print1(z, ", "))))

A385227 Odd multiplicative orders of 4 modulo primes.

Original entry on oeis.org

1, 3, 5, 9, 11, 5, 7, 23, 29, 33, 35, 9, 39, 41, 11, 51, 53, 7, 65, 69, 15, 81, 83, 89, 95, 99, 105, 37, 113, 29, 119, 25, 131, 135, 35, 47, 51, 155, 15, 21, 173, 179, 183, 189, 191, 209, 43, 73, 221, 231, 233, 239, 243, 245, 83, 251, 261, 273, 281, 57, 293
Offset: 1

Views

Author

Jianing Song, Jun 22 2025

Keywords

Comments

a(n) is the multiplicative order of 4 modulo A385221(n).
Odd elements in A082654.

Links

Crossrefs

Cf. A082654, A385221 (corresponding primes).
Cf. other bases: A139686 (base 2), A385226 (base 3), this sequence (base 4), A385193 (base 5), A385228 (base -2), A385229 (base -3), A385230 (base -4), A385231 (base -5).

Programs

  • Mathematica
    Select[Map[MultiplicativeOrder[4, #] &, Prime[Range[200]]], OddQ] (* Paolo Xausa, Jun 28 2025 *)
  • PARI
    forprime(p=3, 1e4, z=znorder(Mod(4, p)); if(z%2, print1(z, ", ")))

A385228 Odd multiplicative orders of -2 modulo primes.

Original entry on oeis.org

1, 5, 9, 7, 29, 33, 41, 53, 65, 69, 81, 89, 105, 113, 25, 35, 47, 51, 15, 173, 189, 209, 221, 233, 245, 83, 261, 273, 281, 57, 293, 77, 309, 107, 329, 11, 115, 123, 393, 135, 413, 429, 441, 453, 473, 97, 509, 129, 131, 175, 545, 137, 561, 83, 585, 593, 149, 629, 641, 645, 653, 713, 725
Offset: 1

Views

Author

Jianing Song, Jun 22 2025

Keywords

Comments

a(n) is the multiplicative order of -2 modulo A163183(n).
Odd elements in A337878 (with first term changed to 1).

Links

Crossrefs

Cf. A337878, A163183 (corresponding primes).
Cf. other bases: A139686 (base 2), A385226 (base 3), A385227 (base 4), A385193 (base 5), this sequence (base -2), A385229 (base -3), A385230 (base -4), A385231 (base -5).

Programs

  • Mathematica
    Select[Map[MultiplicativeOrder[-2, #] &, Prime[Range[250]]], OddQ] (* Paolo Xausa, Jun 28 2025 *)
  • PARI
    forprime(p=3, 1e4, z=znorder(Mod(-2, p)); if(z%2, print1(z, ", ")))

A385229 Odd multiplicative orders of -3 modulo primes.

Original entry on oeis.org

1, 3, 9, 15, 9, 21, 5, 11, 39, 17, 63, 69, 25, 39, 81, 99, 105, 111, 15, 141, 17, 165, 87, 61, 93, 189, 99, 73, 231, 243, 83, 29, 7, 285, 303, 51, 103, 315, 107, 11, 345, 121, 369, 375, 131, 405, 411, 71, 429, 219, 63, 453, 153, 117, 161, 165, 83, 17, 519, 105, 531, 267, 543, 561, 117
Offset: 1

Views

Author

Jianing Song, Jun 22 2025

Keywords

Comments

Odd elements in A380482.
a(n) is the multiplicative order of -3 modulo A385223(n).

Links

Crossrefs

Cf. A380482, A385223 (corresponding primes).
Cf. other bases: A139686 (base 2), A385226 (base 3), A385227 (base 4), A385193 (base 5), A385228 (base -2), this sequence (base -3), A385230 (base -4), A385231 (base -5).

Programs

  • Mathematica
    Select[Map[MultiplicativeOrder[-3, #] &, Prime[Range[200]]], OddQ] (* Paolo Xausa, Jun 30 2025 *)
  • PARI
    forprime(p=2, 1e4, if(p!=3, z=znorder(Mod(-3, p)); if(z%2, print1(z, ", "))))

A385230 Odd multiplicative orders of -4 modulo primes.

Original entry on oeis.org

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

Views

Author

Jianing Song, Jun 22 2025

Keywords

Comments

Odd elements in A380531.
a(n) is the multiplicative order of -4 modulo A385224(n).

Links

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).

Programs

  • Mathematica
    Select[Map[MultiplicativeOrder[-4, #] &, Prime[Range[200]]], OddQ] (* Paolo Xausa, Jun 30 2025 *)
  • PARI
    forprime(p=3, 1e4, z=znorder(Mod(-4, p)); if(z%2, print1(z, ", ")))

A385231 Odd multiplicative orders of -5 modulo primes.

Original entry on oeis.org

1, 1, 3, 11, 7, 21, 23, 15, 11, 41, 51, 53, 21, 27, 83, 111, 113, 57, 131, 141, 153, 173, 87, 61, 191, 105, 221, 7, 231, 233, 27, 251, 127, 5, 261, 273, 281, 293, 303, 107, 323, 165, 341, 175, 177, 363, 371, 19, 393, 205, 137, 59, 431, 63, 443, 453, 473, 483, 491, 177, 181, 551, 277, 187, 141
Offset: 1

Views

Author

Jianing Song, Jun 22 2025

Keywords

Comments

Odd elements in A380532.
a(n) is the multiplicative order of -5 modulo A385225(n).

Links

Crossrefs

Cf. A380532, A385225 (corresponding primes).
Cf. other bases: A139686 (base 2), A385226 (base 3), A385227 (base 4), A385193 (base 5), A385228 (base -2), A385229 (base -3), A385230 (base -4), this sequence (base -5).

Programs

  • Mathematica
    Select[Map[MultiplicativeOrder[-5, #] &, Prime[Range[200]]], OddQ] (* Paolo Xausa, Jun 30 2025 *)
  • PARI
    forprime(p=2, 1e4, if(p!=5, z=znorder(Mod(-5, p)); if(z%2, print1(z, ", "))))
Showing 1-8 of 8 results.

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