A204115 - OEIS

A204115

Array: row n shows the coefficients of the characteristic polynomial of the n-th principal submatrix from A204114, given by gcd(L(i+1), L(j+1)), where L=A000032 (Lucas numbers).

1, -1, 2, -4, 1, 6, -16, 8, -1, 36, -108, 69, -15, 1, 360, -1152, 834, -230, 26, -1, 5280, -17696, 14368, -4668, 682, -44, 1, 147840, -506048, 426568, -147856, 24262, -1952, 73, -1, 6800640, -23573888, 20317360

(list; table; graph; refs; listen; history; text; internal format)

OFFSET

1,3

COMMENTS

Let p(n)=p(n,x) be the characteristic polynomial of the n-th principal submatrix. The zeros of p(n) are real, and they interlace the zeros of p(n+1). See A202605 and A204016 for guides to related sequences.

REFERENCES

(For references regarding interlacing roots, see A202605.)

LINKS

Table of n, a(n) for n=1..38.

EXAMPLE

Top of the array:

1, -1;

2, -4, 1;

6, -16, 8, -1;

36, -108, 69, -15, 1;

MATHEMATICA

u[n_] := LucasL[n]