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 1-10 of 10 results.

A218357 Minimal order of degree-n irreducible polynomials over GF(5).

Original entry on oeis.org

1, 3, 31, 13, 11, 7, 19531, 32, 19, 33, 12207031, 91, 305175781, 29, 181, 17, 409, 27, 191, 41, 379, 23, 8971, 224, 101, 5227, 109, 377, 59, 61, 1861, 128, 199, 1227, 211, 37, 149, 573, 79, 241, 2238236249, 43, 1644512641, 89, 209, 47, 177635683940025046467781066894531
Offset: 1

Views

Author

Alois P. Heinz, Oct 27 2012

Keywords

Comments

a(n) < 5^n.
a(n) <= A143665(n). For prime n, a(n) = A143665(n). - Max Alekseyev, Apr 30 2022

Crossrefs

Programs

  • Maple
    with(numtheory):
    M:= proc(n) M(n):= divisors(5^n-1) minus U(n-1) end:
    U:= proc(n) U(n):= `if`(n=0, {}, M(n) union U(n-1)) end:
    a:= n-> min(M(n)[]):
    seq(a(n), n=1..47);
  • Mathematica
    M[n_] := M[n] = Divisors[5^n - 1] ~Complement~ U[n-1];
    U[n_] := U[n] = If[n == 0, {}, M[n] ~Union~ U[n-1]];
    a[n_] := Min[M[n]];
    Table[a[n], {n, 1, 47}] (* Jean-François Alcover, Mar 24 2017, translated from Maple *)

Formula

a(n) = min(M(n)) with M(n) = {d : d|(5^n-1)} \ U(n-1) and U(n) = M(n) union U(n-1) for n>0, U(0) = {}.
a(n) = A212485(n,1) = A213224(n,3).

A218358 Minimal order of degree-n irreducible polynomials over GF(7).

Original entry on oeis.org

1, 4, 9, 5, 2801, 36, 29, 64, 27, 11, 1123, 13, 16148168401, 113, 31, 17, 14009, 108, 419, 55, 261, 23, 47, 73, 2551, 53, 81, 145, 59, 99, 311, 256, 3631, 56036, 81229, 135, 223, 1676, 486643, 41, 83, 1017, 166003607842448777, 115, 837, 188, 13722816749522711
Offset: 1

Views

Author

Alois P. Heinz, Oct 27 2012

Keywords

Comments

a(n) < 7^n.

Crossrefs

Programs

  • Maple
    with(numtheory):
    M:= proc(n) M(n):= divisors(7^n-1) minus U(n-1) end:
    U:= proc(n) U(n):= `if`(n=0, {}, M(n) union U(n-1)) end:
    a:= n-> min(M(n)[]):
    seq(a(n), n=1..42);
  • Mathematica
    M[n_] := M[n] = Divisors[7^n - 1]~Complement~U[n - 1];
    U[n_] := U[n] = If[n == 0, {}, M[n]~Union~U[n - 1]];
    a[n_] := Min[M[n]];
    Table[a[n], {n, 1, 47}] (* Jean-François Alcover, Oct 24 2022, after Alois P. Heinz *)

Formula

a(n) = min(M(n)) with M(n) = {d : d|(7^n-1)} \ U(n-1) and U(n) = M(n) union U(n-1) for n>0, U(0) = {}.
a(n) = A212486(n,1) = A213224(n,4).

A218356 Minimal order of degree-n irreducible polynomials over GF(3).

Original entry on oeis.org

1, 4, 13, 5, 11, 7, 1093, 32, 757, 44, 23, 35, 797161, 547, 143, 17, 1871, 19, 1597, 25, 14209, 67, 47, 224, 8951, 398581, 109, 29, 59, 31, 683, 128, 299, 103, 71, 95, 13097927, 2851, 169, 352, 83, 43, 431, 115, 181, 188, 1223, 97, 491, 151, 12853, 53, 107
Offset: 1

Views

Author

Alois P. Heinz, Oct 27 2012

Keywords

Comments

a(n) < 3^n.
For n > 2, a(n) <= A143663(n). For odd prime n, a(n) = A143663(n). - Max Alekseyev, Apr 30 2022

Crossrefs

Programs

  • Maple
    M:= proc(n) M(n):= numtheory[divisors](3^n-1) minus U(n-1) end:
    U:= proc(n) U(n):= `if`(n=0, {}, M(n) union U(n-1)) end:
    a:= n-> min(M(n)[]):
    seq(a(n), n=1..60);
  • Mathematica
    M[n_] := M[n] = Divisors[3^n - 1]~Complement~U[n - 1];
    U[n_] := U[n] = If[n == 0, {}, M[n]~Union~U[n - 1]];
    a[n_] := Min[M[n]];
    Table[a[n], {n, 1, 60}] (* Jean-François Alcover, Oct 24 2022, after Alois P. Heinz *)

Formula

a(n) = min(M(n)) with M(n) = {d : d|(3^n-1)} \ U(n-1) and U(n) = M(n) union U(n-1) for n>0, U(0) = {}.
a(n) = A212906(n,1) = A213224(n,2).

A212953 Minimal order of degree-n irreducible polynomials over GF(2).

Original entry on oeis.org

1, 3, 7, 5, 31, 9, 127, 17, 73, 11, 23, 13, 8191, 43, 151, 257, 131071, 19, 524287, 25, 49, 69, 47, 119, 601, 2731, 262657, 29, 233, 77, 2147483647, 65537, 161, 43691, 71, 37, 223, 174763, 79, 187, 13367, 147, 431, 115, 631, 141, 2351, 97, 4432676798593, 251
Offset: 1

Views

Author

Alois P. Heinz, Jun 01 2012

Keywords

Comments

a(n) = smallest odd m such that A002326((m-1)/2) = n. - Thomas Ordowski, Feb 04 2014
For n > 1; n < a(n) < 2^n, wherein a(n) = n+1 iff n+1 is A001122 a prime with primitive root 2, or a(n) = 2^n-1 iff n is a Mersenne exponent A000043. - Thomas Ordowski, Feb 08 2014

Examples

			For n=4 the degree-4 irreducible polynomials p over GF(2) are 1+x+x^2+x^3+x^4, 1+x+x^4, 1+x^3+x^4. Their orders (i.e., the smallest integer e for which p divides x^e+1) are 5, 15, 15. (Example: (1+x+x^2+x^3+x^4) * (1+x) == x^5+1 (mod 2)). Thus the minimal order is 5 and a(4) = 5.
		

References

  • W. Narkiewicz, Elementary and Analytic Theory of Algebraic Numbers, Springer 2004, Third Edition, 4.3 Factorization of Prime Ideals in Extensions. More About the Class Group (Theorem 4.33), 4.4 Notes to Chapter 4 (Theorem 4.40). - Regarding the first comment.

Crossrefs

Programs

  • Maple
    with(numtheory):
    M:= proc(n) option remember;
          divisors(2^n-1) minus U(n-1)
        end:
    U:= proc(n) option remember;
          `if`(n=0, {}, M(n) union U(n-1))
        end:
    a:= n-> min(M(n)[]):
    seq(a(n), n=1..50);
  • Mathematica
    M[n_] := M[n] = Divisors[2^n-1] ~Complement~ U[n-1];
    U[n_] := U[n] = If[n == 0, {}, M[n] ~Union~ U[n-1]];
    a[n_] := Min[M[n]];
    Array[a, 50] (* Jean-François Alcover, Mar 22 2017, translated from Maple *)

Formula

a(n) = min(M(n)) with M(n) = {d : d|(2^n-1)} \ U(n-1) and U(n) = M(n) union U(n-1) for n>0, U(0) = {}.
a(n) = A059912(n,1) = A213224(n,1).

A218359 Minimal order of degree-n irreducible polynomials over GF(11).

Original entry on oeis.org

1, 3, 7, 16, 25, 9, 43, 32, 1772893, 75, 15797, 13, 1093, 129, 175, 17, 50544702849929377, 27, 6115909044841454629, 400, 49, 23, 829, 224, 125, 53, 5559917315850179173, 29, 523, 31, 50159, 128, 661, 71707, 211, 351, 2591, 191, 79, 41, 83, 147, 1416258521793067
Offset: 1

Views

Author

Alois P. Heinz, Oct 27 2012

Keywords

Comments

a(n) < 11^n.

Crossrefs

Programs

  • Maple
    with(numtheory):
    M:= proc(n) M(n):= divisors(11^n-1) minus U(n-1) end:
    U:= proc(n) U(n):= `if`(n=0, {}, M(n) union U(n-1)) end:
    a:= n-> min(M(n)[]):
    seq(a(n), n=1..42);
  • Mathematica
    M[n_] := M[n] = Divisors[11^n - 1]~Complement~U[n - 1];
    U[n_] := U[n] = If[n == 0, {}, M[n]~Union~U[n - 1]];
    a[n_] := Min[M[n]];
    Table[a[n], {n, 1, 43}] (* Jean-François Alcover, Oct 24 2022, after Alois P. Heinz *)

Formula

a(n) = min(M(n)) with M(n) = {d : d|(11^n-1)} \ U(n-1) and U(n) = M(n) union U(n-1) for n>0, U(0) = {}.
a(n) = A218336(n,1) = A213224(n,5).

A218360 Minimal order of degree-n irreducible polynomials over GF(13).

Original entry on oeis.org

1, 7, 9, 5, 30941, 63, 5229043, 32, 27, 11, 23, 45, 53, 29, 4651, 64, 103, 19, 12865927, 25, 43, 161, 1381, 288, 701, 371, 81, 145, 1973, 31, 311, 128, 207, 721, 211, 37, 1481, 90061489, 79, 41, 6740847065723, 261, 119627, 115, 181, 47, 183959, 576, 1667, 101
Offset: 1

Views

Author

Alois P. Heinz, Oct 27 2012

Keywords

Comments

a(n) < 13^n.

Crossrefs

Programs

  • Maple
    with(numtheory):
    M:= proc(n) M(n):= divisors(13^n-1) minus U(n-1) end:
    U:= proc(n) U(n):= `if`(n=0, {}, M(n) union U(n-1)) end:
    a:= n-> min(M(n)[]):
    seq(a(n), n=1..33);
  • Mathematica
    M[n_] := M[n] = Divisors[13^n - 1]~Complement~U[n - 1];
    U[n_] := U[n] = If[n == 0, {}, M[n]~Union~U[n - 1]];
    a[n_] := Min[M[n]];
    Table[a[n], {n, 1, 50}] (* Jean-François Alcover, Oct 24 2022, after Alois P. Heinz *)

Formula

a(n) = min(M(n)) with M(n) = {d : d|(13^n-1)} \ U(n-1) and U(n) = M(n) union U(n-1) for n>0, U(0) = {}.
a(n) = A218337(n,1) = A213224(n,6).

A218361 Minimal order of degree-n irreducible polynomials over GF(17).

Original entry on oeis.org

1, 3, 307, 5, 88741, 7, 25646167, 128, 19, 11, 2141993519227, 35, 212057, 22796593, 27243487, 256, 10949, 57, 229, 25, 43, 23, 47, 73, 2551, 53, 433, 5766433, 59, 31, 4093, 257, 67, 32847, 966211, 37, 149, 457, 157, 41, 83, 49, 1549, 89, 3691, 141
Offset: 1

Views

Author

Alois P. Heinz, Oct 27 2012

Keywords

Comments

a(n) < 17^n.

Crossrefs

Programs

  • Maple
    with(numtheory):
    M:= proc(n) M(n):= divisors(17^n-1) minus U(n-1) end:
    U:= proc(n) U(n):= `if`(n=0, {}, M(n) union U(n-1)) end:
    a:= n-> min(M(n)[]):
    seq(a(n), n=1..35);
  • Mathematica
    M[n_] := M[n] = Divisors[17^n-1] ~Complement~ U[n-1];
    U[n_] := U[n] = If[n == 0, {}, M[n] ~Union~ U[n-1]];
    a[n_] := a[n] = Min[M[n]];
    Table[Print[n, " ", a[n]]; a[n], {n, 1, 60}] (* Jean-François Alcover, Oct 21 2022, after Maple code *)

Formula

a(n) = min(M(n)) with M(n) = {d : d|(17^n-1)} \ U(n-1) and U(n) = M(n) union U(n-1) for n>0, U(0) = {}.
a(n) = A218338(n,1) = A213224(n,7).

A218362 Minimal order of degree-n irreducible polynomials over GF(19).

Original entry on oeis.org

1, 4, 27, 16, 151, 7, 701, 17, 81, 11, 104281, 13, 599, 197, 31, 64, 3044803, 199, 109912203092239643840221, 176, 18927, 23, 277, 119, 101, 131, 243, 29, 59, 61, 243270318891483838103593381595151809701, 97, 67, 12179212, 71, 37, 149, 108301, 79, 41, 10654507
Offset: 1

Views

Author

Alois P. Heinz, Oct 27 2012

Keywords

Comments

a(n) < 19^n.

Crossrefs

Programs

  • Maple
    with(numtheory):
    M:= proc(n) M(n):= divisors(19^n-1) minus U(n-1) end:
    U:= proc(n) U(n):= `if`(n=0, {}, M(n) union U(n-1)) end:
    a:= n-> min(M(n)[]):
    seq(a(n), n=1..28);
  • Mathematica
    M[n_] := M[n] = Divisors[19^n - 1]~Complement~U[n - 1];
    U[n_] := U[n] = If[n == 0, {}, M[n]~Union~U[n - 1]];
    a[n_] := Min[M[n]];
    Table[a[n], {n, 1, 41}] (* Jean-François Alcover, Oct 24 2022, after Alois P. Heinz *)

Formula

a(n) = min(M(n)) with M(n) = {d : d|(19^n-1)} \ U(n-1) and U(n) = M(n) union U(n-1) for n>0, U(0) = {}.
a(n) = A218339(n,1) = A213224(n,8).

A218363 Minimal order of degree-n irreducible polynomials over GF(23).

Original entry on oeis.org

1, 3, 7, 5, 292561, 9, 29, 64, 19, 31, 121, 35, 47691619, 71, 2047927, 17, 103, 27, 2129, 25, 43, 363, 461, 448, 6551, 143074857, 4591, 145, 233, 151, 40888990028603, 193, 67, 239, 8484269, 73, 1925658337781, 6387, 333841333, 1600, 83, 129, 173, 605, 5558659
Offset: 1

Views

Author

Alois P. Heinz, Oct 27 2012

Keywords

Comments

a(n) < 23^n.

Crossrefs

Programs

  • Maple
    with(numtheory):
    M:= proc(n) M(n):= divisors(23^n-1) minus U(n-1) end:
    U:= proc(n) U(n):= `if`(n=0, {}, M(n) union U(n-1)) end:
    a:= n-> min(M(n)[]):
    seq(a(n), n=1..30);
  • Mathematica
    M[n_] := M[n] = Divisors[23^n - 1]~Complement~U[n - 1];
    U[n_] := U[n] = If[n == 0, {}, M[n]~Union~U[n - 1]];
    a[n_] := Min[M[n]];
    Table[Print[n, " ", a[n]]; a[n], {n, 1, 45}] (* Jean-François Alcover, Oct 24 2022, after Alois P. Heinz *)

Formula

a(n) = min(M(n)) with M(n) = {d : d|(23^n-1)} \ U(n-1) and U(n) = M(n) union U(n-1) for n>0, U(0) = {}.
a(n) = A218340(n,1) = A213224(n,9).

A218364 Minimal order of degree-n irreducible polynomials over GF(29).

Original entry on oeis.org

1, 3, 13, 16, 732541, 9, 49, 32, 14437, 11, 23, 37, 521, 147, 181, 17, 3911, 19, 1386659, 176, 637, 69, 131327761273, 288, 151, 53, 52813, 784, 59, 99, 36767, 128, 299, 1973, 71, 304, 149, 16759, 169, 41, 83, 43, 173, 368, 2613097, 47, 283, 153, 197, 125, 103
Offset: 1

Views

Author

Alois P. Heinz, Oct 27 2012

Keywords

Comments

a(n) < 29^n.

Crossrefs

Programs

  • Maple
    with(numtheory):
    M:= proc(n) M(n):= divisors(29^n-1) minus U(n-1) end:
    U:= proc(n) U(n):= `if`(n=0, {}, M(n) union U(n-1)) end:
    a:= n-> min(M(n)[]):
    seq(a(n), n=1..10);
  • Mathematica
    M[n_] := M[n] = Divisors[29^n - 1]~Complement~U[n - 1];
    U[n_] := U[n] = If[n == 0, {}, M[n]~Union~U[n - 1]];
    a[n_] := Min[M[n]];
    Table[Print[n, " ", a[n]]; a[n], {n, 1, 51}] (* Jean-François Alcover, Oct 24 2022, after Alois P. Heinz *)

Formula

a(n) = min(M(n)) with M(n) = {d : d|(29^n-1)} \ U(n-1) and U(n) = M(n) union U(n-1) for n>0, U(0) = {}.
a(n) = A218341(n,1) = A213224(n,10).
Showing 1-10 of 10 results.