A207967 Numbers that match non-irreducible polynomials over {0,1,2}; complement of A207966.

1, 2, 9, 12, 15, 16, 18, 21, 24, 27, 28, 30, 32, 33, 36, 39, 40, 42, 44, 45, 48, 50, 51, 52, 54, 56, 57, 60, 63, 64, 66, 68, 69, 70, 72, 75, 76, 78, 80, 81, 84, 87, 88, 90, 91, 93, 96, 99, 100, 102, 104, 105, 108, 111, 112, 114, 116, 117, 119, 120, 123, 124

Offset: 1

Author

Clark Kimberling, Feb 21 2012

Keywords

• nonn

Comments

See A207966.

Examples

			(See A207966.)
		

Crossrefs

Cf. A207966, A207968.

Programs

Mathematica

t = Table[IntegerDigits[n, 3], {n, 1, 850}];
b[n_] := Reverse[Table[x^k, {k, 0, n}]]
p[n_, x_] := t[[n]].b[-1 + Length[t[[n]]]]
Table[p[n, x], {n, 1, 15}]
u = {}; Do[n++; If[IrreduciblePolynomialQ[p[n, x]],
  AppendTo[u, n]], {n, 300}]; u  (* A207966 *)
Complement[Range[200], u]        (* A207967 *)
b[n_] := FromDigits[IntegerDigits[u, 3][[n]]]
Table[b[n], {n, 1, 50}]          (* A207968 *)