login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A207670 Numbers that match polynomials with coefficients in {0,1,2} that are not irreducible modulo 3; complement of A207670. 5
1, 2, 9, 11, 12, 13, 15, 16, 18, 19, 21, 23, 24, 26, 27, 28, 29, 30, 31, 32, 33, 36, 37, 39, 40, 42, 44, 45, 47, 48, 50, 51, 52, 54, 55, 56, 57, 60, 61, 62, 63, 64, 66, 68, 69, 70, 72, 74, 75, 76, 78, 80, 81, 82, 83, 84, 85, 87, 88, 90, 91, 93, 95, 96, 98, 99, 100 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
See the Comments at A207669.
LINKS
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
Cf. A207669.
Sequence in context: A363951 A085069 A371163 * A176545 A072065 A137000
KEYWORD
nonn
AUTHOR
Clark Kimberling, Feb 26 2012
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 18 21:02 EDT 2024. Contains 374388 sequences. (Running on oeis4.)