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A192233 Constant term of the reduction of the n-th cyclotomic polynomial by x^2->x+1. 2
-1, 1, 2, 2, 5, 2, 13, 3, 7, 3, 89, 2, 233, 5, 8, 14, 1597, 5, 4181, 10, 47, 23, 28657, 12, 4596, 57, 1619, 65, 514229, 16, 1346269, 611, 2102, 379, 12461, 85, 24157817, 989, 14357, 533, 165580141, 113, 433494437, 3026, 22201, 6767, 2971215073, 598, 171486453, 3836 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

See A192232.

LINKS

Table of n, a(n) for n=1..50.

MATHEMATICA

q[x_] := x + 1;

reductionRules = {x^y_?EvenQ -> q[x]^(y/2),

   x^y_?OddQ -> x q[x]^((y - 1)/2)};

t = Table[

   Last[Most[

     FixedPointList[Expand[#1 /. reductionRules] &,

      Cyclotomic[n, x]]]], {n, 1, 50}];

Table[Coefficient[Part[t, n], x, 0], {n, 1, 50}]  (* A192233 *)

Table[Coefficient[Part[t, n], x, 1], {n, 1,

  50}]  (* A051258 Fibocyclotomic numbers *)

(* by Peter J. C. Moses, Jun 25 2011 *)

CROSSREFS

Cf. A192232.

Sequence in context: A213642 A303073 A068058 * A144943 A114976 A085483

Adjacent sequences:  A192230 A192231 A192232 * A192234 A192235 A192236

KEYWORD

sign

AUTHOR

Clark Kimberling, Jun 26 2011

STATUS

approved

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Last modified December 17 14:12 EST 2018. Contains 318201 sequences. (Running on oeis4.)