login
A140885
Triangle T(n,k) read by rows: the coefficient [x^k] ( Phi(n,x)+x^n*Phi(n,1/x)) related to cyclotomic polynomials Phi(n,x).
0
0, 0, 0, 1, 2, 1, 1, 2, 2, 1, 1, 0, 2, 0, 1, 1, 2, 2, 2, 2, 1, 1, -1, 1, 0, 1, -1, 1, 1, 2, 2, 2, 2, 2, 2, 1, 1, 0, 0, 0, 2, 0, 0, 0, 1, 1, 0, 0, 2, 0, 0, 2, 0, 0, 1, 1, -1, 1, -1, 1, 0, 1, -1, 1, -1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 0, -1, 0, 1, 0, 0, 0, 1, 0, -1, 0, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, -1, 1
OFFSET
0,5
COMMENTS
Row sums are: 0, 0, 4, 6, 4, 10, 2, 14, 4, 6, 2, 22, 2, 26, 2, 2, 4, 34, 2, 38, 2,...
FORMULA
T(n,k) = T(n,n-k) .
EXAMPLE
0; # x+x^0*(1/x) = x+1/x
0, 0; # x-1+x*(1/x-1) = 0
1, 2, 1; # x+1+x^2*(1/x+1) = 1+2*x+x^2
1, 2, 2, 1;
1, 0, 2, 0, 1;
1, 2, 2, 2, 2, 1;
1, -1, 1, 0, 1, -1, 1;
1, 2, 2, 2, 2, 2, 2, 1;
1, 0, 0, 0, 2, 0, 0, 0, 1;
1, 0, 0, 2, 0, 0, 2, 0, 0, 1;
1, -1, 1, -1, 1, 0, 1, -1, 1, -1, 1;
MATHEMATICA
Clear[p, x, n, m, a]; p[x_, n_] := Cyclotomic[n, x] + ExpandAll[x^n*Cyclotomic[n, 1/x]]; Table[p[x, n], {n, 0, 10}]; a = Table[CoefficientList[p[x, n], x], {n, 0, 10}]; Flatten[a]
CROSSREFS
Cf. A013595.
Sequence in context: A190672 A327910 A242998 * A064286 A002471 A218622
KEYWORD
tabl,sign
AUTHOR
EXTENSIONS
All entries replaced to comply with the definition and examples - The Assoc. Eds. of the OEIS, Oct 12 2010
STATUS
approved