|
|
A094754
|
|
Middle coefficient of cyclotomic polynomial Phi_n(x).
|
|
3
|
|
|
0, 0, 1, 0, 1, -1, 1, 0, 1, 1, 1, -1, 1, -1, -1, 0, 1, -1, 1, 1, 1, -1, 1, -1, 1, 1, 1, -1, 1, -1, 1, 0, -1, 1, 1, -1, 1, -1, 1, 1, 1, 1, 1, -1, -1, -1, 1, -1, 1, 1, -1, 1, 1, -1, 1, -1, 1, 1, 1, -1, 1, -1, 1, 0, -1, -1, 1, 1, -1, 1, 1, -1, 1, 1, -1, -1, -1, 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, 1, -1, -1, -1, 1, -1, -1, -1, 1, -1, -1, 1, 1, -1, 1, 1, -1
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,385
|
|
COMMENTS
|
a(n) = 0 if n is a power of 2, otherwise a(n) is odd.
The first term with absolute value > 1 is a(385) = -3. - Michel Marcus, Apr 24 2019
|
|
LINKS
|
|
|
MAPLE
|
with(numtheory); t1:=[0, 0]; for n from 3 to 120 do t2:=cyclotomic(n, x); t3:=degree(t2, x); t1:=[op(t1), coeff(t2, x, floor(t3/2))]; od: t1;
|
|
MATHEMATICA
|
Array[If[EvenQ@ Length@ #, 0, #[[Ceiling[Length[#]/2] ]] ] &@ CoefficientList[Cyclotomic[#, x], x] &, 105] (* Michael De Vlieger, Mar 29 2019 *)
|
|
CROSSREFS
|
Cf. A095877 (n such that the middle coefficient of Phi_n(x) has a value not obtained for smaller n).
|
|
KEYWORD
|
sign
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|