login
A207870
Numbers k matched to Zeckendorf polynomials divisible by x+1.
1
6, 10, 14, 16, 23, 26, 35, 37, 42, 51, 57, 60, 68, 74, 83, 90, 92, 97, 106, 110, 116, 120, 127, 132, 134, 146, 149, 157, 163, 172, 178, 184, 188, 192, 194, 206, 214, 217, 234, 236, 241, 250, 254, 260, 264, 271, 276, 278, 288, 294, 298, 302, 304, 311
OFFSET
1,1
COMMENTS
The Zeckendorf polynomials Z(x,k) are defined and ordered at A207813.
EXAMPLE
The first ten Zeckendorf polynomials are 1, x, x^2, x^2 + 1, x^3, x^3 + 1, x + x^3, x^4, 1 + x^4, x + x^4; their values at x=-1 are 1, -1, 1, 2, -1, 0, -2, 1, 2, 0, indicating initial terms for A207869 and this sequence.
MATHEMATICA
fb[n_] := Block[{k = Ceiling[Log[GoldenRatio, n*Sqrt[5]]],
t = n, fr = {}}, While[k > 1, If[t >= Fibonacci[k],
AppendTo[fr, 1]; t = t - Fibonacci[k],
AppendTo[fr, 0]]; k--]; fr]; t = Table[fb[n],
{n, 1, 500}];
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, 40}]
Table[p[n, x] /. x -> 1, {n, 1, 120}] (* A007895 *)
Table[p[n, x] /. x -> 2, {n, 1, 120}] (* A003714 *)
Table[p[n, x] /. x -> 3, {n, 1, 120}] (* A060140 *)
t1 = Table[p[n, x] /. x -> -1,
{n, 1, 420}] (* A207869 *)
Flatten[Position[t1, 0]] (* this sequence *)
t2 = Table[p[n, x] /. x -> I, {n, 1, 420}];
Flatten[Position[t2, 0] (* A207871 *)
Denominator[Table[p[n, x] /. x -> 1/2,
{n, 1, 120}]] (* A207872 *)
Numerator[Table[p[n, x] /. x -> 1/2,
{n, 1, 120}]] (* A207873 *)
CROSSREFS
Sequence in context: A075777 A315161 A315162 * A315163 A248632 A178246
KEYWORD
nonn
AUTHOR
Clark Kimberling, Feb 21 2012
STATUS
approved