login
A126271
a(n) = order of Galois group of the polynomial P(x) + n if P(x) + n (after dividing by the gcd of its coefficients) is irreducible, otherwise a(n) = 0, where P(x) = 128*x^8 - 256*x^6 + 160*x^4 - 32*x^2 + 1.
1
32, 32, 16, 32, 32, 32, 32, 32, 32, 16, 32, 32, 32, 16, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 16, 16, 32, 32, 32
OFFSET
0,1
COMMENTS
P(x) = T_8(x) is the degree 8 Chebyshev polynomial of the first kind.
LINKS
PROG
(Magma) Q:=RationalField(); R<x>:=PolynomialRing(Q); f:=128*x^8 - 256*x^6 + 160*x^4 - 32*x^2 + 0; for n in {0 .. 30} do f:=f+1; Order(GaloisGroup(f)); end for; /* N. J. A. Sloane */
CROSSREFS
Sequence in context: A131762 A208129 A330574 * A010871 A248767 A022366
KEYWORD
nonn
AUTHOR
Artur Jasinski, Dec 23 2006
EXTENSIONS
Edited by N. J. A. Sloane, Dec 28 2007
STATUS
approved