A126570 Triangle read by rows: row n gives coefficients (ignoring the alternating signs) of the characteristic polynomial of the n X n circulant matrix with first two rows [2,1,0,...,0,1], [1,2,1,0,...,0].

1, 1, 2, 1, 4, 3, 1, 6, 10, 5, 1, 8, 21, 20, 4, 1, 10, 36, 56, 35, 7, 1, 12, 55, 120, 126, 56, 6

Offset

1,3

References

William G. Harter, Physics Department, University of Arkansas; personal communication.

Links

Table of n, a(n) for n=1..28.

Example

First few rows of the triangle are:
1;
1, 2;
1, 4, 3;
1, 6, 10, 5;
1, 8, 21, 20, 4;
1, 10, 36, 56, 35, 7;
1, 12, 55, 120, 126, 56, 6;
...
Example: Charpoly of the 4 X 4 matrix [2,1,0,1; 1,2,1,0; 0,1,2,1; 0,0,1,2] = x^4 - 8*x^3 + 21*x^2 - 20*x + 4; with a root sqrt(3)+2.

Crossrefs

Sequence in context: A172431 A053123 A107661 * A048790 A027421 A131252

Adjacent sequences: A126567 A126568 A126569 * A126571 A126572 A126573

Keyword

nonn,more,tabl

Author

Gary W. Adamson, Dec 28 2006

Extensions

Edited by N. J. A. Sloane, Aug 10 2019

Status

approved