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.

A058944 Coefficients of monic irreducible polynomials over GF(3) listed in lexicographic order.

Original entry on oeis.org

10, 11, 12, 101, 112, 122, 1021, 1022, 1102, 1112, 1121, 1201, 1211, 1222, 10012, 10022, 10102, 10111, 10121, 10202, 11002, 11021, 11101, 11111, 11122, 11222, 12002, 12011, 12101, 12112, 12121, 12212, 100021, 100022, 100112, 100211
Offset: 1

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Author

N. J. A. Sloane, Jan 13 2001

Keywords

Examples

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

References

  • R. Lidl and H. Niederreiter, Finite Fields, Addison-Wesley, 1983, Table C, pp. 555-557.

Crossrefs

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

Programs

  • Maple
    N:= 100: # to get the first N terms
    count:= 0:
    for d from 1 while count < N do
    for nn from 0 to 3^d-1 while count < N do
      L:= convert(nn,base,3);
      P:= add(L[i]*x^(i-1),i=1..nops(L))+x^d;
      if Irreduc(P) mod 3 then
         count:= count+1;
         A[count]:= add(L[i]*10^(i-1),i=1..nops(L))+10^d;
      fi
      od
    od:
    seq(A[i],i=1..N); # Robert Israel, Jul 06 2016
  • Mathematica
    A058944 = Union[ Reap[ Do[ a = Reverse[ IntegerDigits[n, 3]]; b = {0}; la = Length[a]; k = 1; While[k < la+1, b = Append[ b, a[[k]]*x^(k-1)]; k++]; b = Plus @@ b; c = Factor[ b, Modulus -> 3]; id = IntegerDigits[n, 3]; If[b == c && (id == {1, 0} || id[[-1]] != 0), Sow[ FromDigits[id] ] ], {n, 3, 300}]][[2, 1]]](* Jean-François Alcover, Feb 13 2012, after A058943 *)

Extensions

More terms from David Wasserman, May 23 2002