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.

A058947 Coefficients of primitive irreducible polynomials over GF(2) listed in lexicographic order.

Original entry on oeis.org

11, 111, 1011, 1101, 10011, 11001, 100101, 101001, 101111, 110111, 111011, 111101, 1000011, 1011011, 1100001, 1100111, 1101101, 1110011, 10000011, 10001001, 10001111, 10010001, 10011101, 10100111, 10101011
Offset: 1

Views

Author

N. J. A. Sloane, Jan 13 2001

Keywords

Comments

Church's table extends through degree 11.

Examples

			The first few are x+1; x^2+x+1; x^3+x+1, x^3+x^2+1; ... Note that x is irreducible but not primitive.
		

Crossrefs

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.
a(n) = A007088(A091250(n)).

Programs

  • Mathematica
    car = 2; maxDegree = 13;
    okQ[{1, 1}] = True;
    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 09 2019 *)