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.

Previous Showing 11-14 of 14 results.

A058951 Coefficients of monic primitive irreducible polynomials over GF(7) listed in lexicographic order.

Original entry on oeis.org

12, 14, 113, 123, 125, 135, 145, 153, 155, 163, 1032, 1052, 1062, 1112, 1124, 1152, 1154, 1214, 1242, 1262, 1264, 1304, 1314, 1322, 1334, 1352, 1354, 1362, 1422, 1432, 1434, 1444, 1504, 1524, 1532, 1534, 1542, 1552, 1564, 1604, 1612, 1632, 1644, 1654
Offset: 1

Views

Author

N. J. A. Sloane, Jan 13 2001

Keywords

Crossrefs

Cf. A058946.
Irreducible over GF(2), GF(3), GF(4), GF(5), GF(7): A058943, A058944, A058948, A058945, A058946. Primitive irreducible over GF(2), GF(3), GF(4), GF(5), GF(7): A058947, A058949, A058952, A058950, A058951.

Programs

  • Mathematica
    car = 7; maxDegree = 4;
    okQ[coefs_List] := Module[{P}, P = coefs.x^Range[Length[coefs] - 1, 0, -1]; coefs[[1]] == 1 && IrreduciblePolynomialQ[P, Modulus -> car] && PrimitivePolynomialQ[P, car]];
    FromDigits /@ Select[Table[IntegerDigits[k, car], {k, car+1, car^(maxDegree + 1)}], okQ] (* Jean-François Alcover, Sep 10 2019 *)

Extensions

More terms from Jean Gaumont (jeangaum87(AT)yahoo.com), Apr 16 2006

A212906 Triangle T(n,k) of orders of degree-n irreducible polynomials over GF(3) listed in ascending order.

Original entry on oeis.org

1, 2, 4, 8, 13, 26, 5, 10, 16, 20, 40, 80, 11, 22, 121, 242, 7, 14, 28, 52, 56, 91, 104, 182, 364, 728, 1093, 2186, 32, 41, 82, 160, 164, 205, 328, 410, 656, 820, 1312, 1640, 3280, 6560, 757, 1514, 9841, 19682, 44, 61, 88, 122, 244, 484, 488, 671, 968, 1342
Offset: 1

Views

Author

Boris Putievskiy, May 29 2012

Keywords

Comments

The elements m of row n, are also solutions to the equation: multiplicative order of 3 mod m = n, with gcd(m,3) = 1, cf. A053446.

Examples

			Triangle T(n,k) begins:
1,   2;
4,   8;
13, 26;
5,  10,  16,  20, 40, 80;
11, 22, 121, 242;
7,  14,  28,  52, 56, 91, 104, 182, 364, 728;
		

References

  • R. Lidl and H. Niederreiter, Finite Fields, 2nd ed., Cambridge Univ. Press, 1997, Table C, pp. 555-557.
  • V. I. Arnol'd, Topology and statistics of formulas of arithmetics, Uspekhi Mat. Nauk, 58:4(352) (2003), 3-28

Crossrefs

Column k=2 of A212737.
Column k=1 gives: A218356.

Programs

  • Maple
    with(numtheory):
    M:= proc(n) option remember;
          divisors(3^n-1) minus U(n-1)
        end:
    U:= proc(n) option remember;
          `if`(n=0, {}, M(n) union U(n-1))
        end:
    T:= n-> sort([M(n)[]])[]:
    seq(T(n), n=1..15);  # Alois P. Heinz, Jun 02 2012
  • 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]];
    T[n_] := Sort[M[n]]; Array[T, 15] // Flatten (* Jean-François Alcover, Jun 10 2018, after Alois P. Heinz *)

Formula

T(n,k) = k-th smallest element of M(n) with M(n) = {d : d | (3^n-1)} \ (M(1) U M(2) U ... U M(i-1)) for n>1, M(1) = {1,2}.
|M(n)| = Sum_{d|n} mu(n/d)*tau(3^d-1) = A059885(n).

A212485 Triangle T(n,k) of orders of degree-n irreducible polynomials over GF(5) listed in ascending order.

Original entry on oeis.org

1, 2, 4, 3, 6, 8, 12, 24, 31, 62, 124, 13, 16, 26, 39, 48, 52, 78, 104, 156, 208, 312, 624, 11, 22, 44, 71, 142, 284, 781, 1562, 3124, 7, 9, 14, 18, 21, 28, 36, 42, 56, 63, 72, 84, 93, 126, 168, 186, 217, 248, 252, 279, 372, 434, 504, 558, 651, 744, 868, 1116
Offset: 1

Views

Author

Boris Putievskiy, Jun 02 2012

Keywords

Comments

The elements m of row n, are also solutions to the equation: multiplicative order of 5 mod m = n, with gcd(m,5) = 1, cf. A050977.

Examples

			Triangle T(n,k) begins:
   1,  2,   4;
   3,  6,   8, 12,  24;
  31, 62, 124;
  13, 16,  26, 39,  48,  52,  78,  104,  156, 208, 312, 624;
  11, 22,  44, 71, 142, 284, 781, 1562, 3124;
  ...
		

References

  • R. Lidl and H. Niederreiter, Finite Fields, 2nd ed., Cambridge Univ. Press, 1997, Table C, pp. 557-560.

Crossrefs

Column k=3 of A212737.
Column k=1 gives: A218357.

Programs

  • Maple
    with(numtheory):
    M:= proc(n) option remember;
          `if`(n=1, {1, 2, 4}, divisors(5^n-1) minus U(n-1))
        end:
    U:= proc(n) option remember;
          `if`(n=0, {}, M(n) union U(n-1))
        end:
    T:= n-> sort([M(n)[]])[]:
    seq(T(n), n=1..8);
  • Mathematica
    M[n_] := M[n] = If[n == 1, {1, 2, 4}, Divisors[5^n-1] ~Complement~ U[n-1]];
    U[n_] := U[n] = If[n == 0, {}, M[n] ~Union~ U[n - 1]];
    T[n_] := Sort[M[n]]; Array[T, 8] // Flatten (* Jean-François Alcover, Jun 10 2018, from Maple *)

Formula

T(n,k) = k-th smallest element of M(n) with M(n) = {d : d | (5^n-1)} \ (M(1) U M(2) U ... U M(i-1)) for n>1, M(1) = {1,2,4}.
|M(n)| = Sum_{d|n} mu(n/d)*tau(5^d-1) = A059887.

A212486 Triangle T(n,k) of orders of degree-n irreducible polynomials over GF(7) listed in ascending order.

Original entry on oeis.org

1, 2, 3, 6, 4, 8, 12, 16, 24, 48, 9, 18, 19, 38, 57, 114, 171, 342, 5, 10, 15, 20, 25, 30, 32, 40, 50, 60, 75, 80, 96, 100, 120, 150, 160, 200, 240, 300, 400, 480, 600, 800, 1200, 2400, 2801, 5602, 8403, 16806, 36, 43, 72, 76, 86, 129, 144, 152, 172, 228, 258
Offset: 1

Views

Author

Boris Putievskiy, Jun 02 2012

Keywords

Comments

The elements m of row n, are also solutions to the equation: multiplicative order of 7 mod m = n, with gcd(m,7) = 1, cf. A053450.

Examples

			Triangle T(n,k) begins:
  1,  2,  3,  6;
  4,  8, 12, 16, 24,  48;
  9, 18, 19, 38, 57, 114, 171, 342;
  5, 10, 15, 20, 25,  30,  32,  40, 50, 60, 75, 80, 96, 100, 120, 150, 160, 200, 240, 300, 400, 480, 600, 800, 1200, 2400;
  ...
		

References

  • R. Lidl and H. Niederreiter, Finite Fields, 2nd ed., Cambridge Univ. Press, 1997, Table C, pp. 560-562.
  • V. I. Arnol'd, Topology and statistics of formulas of arithmetics, Uspekhi Mat. Nauk, 58:4(352) (2003), 3-28

Crossrefs

Column k=4 of A212737.
Column k=1 gives: A218358.

Programs

  • Maple
    with(numtheory):
    M:= proc(n) option remember;
          `if`(n=1, {1, 2, 3, 6}, divisors(7^n-1) minus U(n-1))
        end:
    U:= proc(n) option remember;
          `if`(n=0, {}, M(n) union U(n-1))
        end:
    T:= n-> sort([M(n)[]])[]:
    seq(T(n), n=1..7);
  • Mathematica
    M[n_] := M[n] = If[n == 1, {1, 2, 3, 6}, Divisors[7^n - 1] ~Complement~ U[n - 1]];
    U[n_] := U[n] = If[n == 0, {}, M[n] ~Union~ U[n - 1]];
    T[n_] := Sort[M[n]];
    Table[T[n], {n, 1, 7}] // Flatten (* Jean-François Alcover, Sep 24 2022, from Maple code *)

Formula

T(n,k) = k-th smallest element of M(n) with M(n) = {d : d | (7^n-1)} \ (M(1) U M(2) U ... U M(i-1)) for n>1, M(1) = {1,2,3,6}.
|M(n)| = Sum_{d|n} mu(n/d)*tau(7^d-1) = A059889(n).
Previous Showing 11-14 of 14 results.