login
Constant term of the reduction of the n-th cyclotomic polynomial by x^2->x+1.
2

%I #5 Dec 04 2016 19:46:25

%S -1,1,2,2,5,2,13,3,7,3,89,2,233,5,8,14,1597,5,4181,10,47,23,28657,12,

%T 4596,57,1619,65,514229,16,1346269,611,2102,379,12461,85,24157817,989,

%U 14357,533,165580141,113,433494437,3026,22201,6767,2971215073,598,171486453,3836

%N Constant term of the reduction of the n-th cyclotomic polynomial by x^2->x+1.

%C See A192232.

%t q[x_] := x + 1;

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

%t x^y_?OddQ -> x q[x]^((y - 1)/2)};

%t t = Table[

%t Last[Most[

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

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

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

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

%t 50}] (* A051258 Fibocyclotomic numbers *)

%t (* by _Peter J. C. Moses_, Jun 25 2011 *)

%Y Cf. A192232.

%K sign

%O 1,3

%A _Clark Kimberling_, Jun 26 2011