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A207671
Numbers in ternary representation that match nonzero polynomials with all coefficients in {0,1,2} that are irreducible modulo 3.
3
10, 11, 12, 20, 21, 22, 101, 112, 122, 202, 211, 221, 1021, 1022, 1102, 1112, 1121, 1201, 1211, 1222, 2011, 2012, 2102, 2111, 2122, 2201, 2212, 2221, 10012, 10022, 10102, 10111, 10121, 10202, 11002, 11021, 11101, 11111, 11122, 11222
OFFSET
1,1
COMMENTS
For a discussion and examples in base-10 representation, see A207670. For the analogous sequence in base 2, see A206073.
EXAMPLE
(See the Example section of A207669.)
MATHEMATICA
t = Table[IntegerDigits[n, 3], {n, 1, 1000}];
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], Modulus -> 3],
AppendTo[u, n]], {n, 1, 400}]
u (* A207669 *)
Complement[Range[200], %] (* A207670 *)
b[n_] := FromDigits[IntegerDigits[u, 3][[n]]]
Table[b[n], {n, 1, 50}] (* A207671 *)
CROSSREFS
Sequence in context: A305130 A098395 A207968 * A154328 A112654 A362987
KEYWORD
nonn,base
AUTHOR
Clark Kimberling, Feb 26 2012
STATUS
approved