Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
%I #13 Oct 02 2017 09:58:59
%S 1,-1,1,-18,1,1,-84,116,-1,1,-439,1221,-839,1,1,-2475,10435,-13855,
%T 5658,-1,1,-14312,81690,-165715,138669,-39038,1,1,-83270,601411,
%U -1661956,2164099,-1292751,266899,-1,1,-485157
%N Array: row n shows the coefficients of the characteristic polynomial of the n-th principal submatrix of the symmetric matrix A203003; by antidiagonals.
%C Let p(n)=p(n,x) be the characteristic polynomial of the n-th principal submatrix. The zeros of p(n) are positive, and they interlace the zeros of p(n+1).
%H S.-G. Hwang, <a href="http://matrix.skku.ac.kr/Series-E/Monthly-E.pdf">Cauchy's interlace theorem for eigenvalues of Hermitian matrices</a>, American Mathematical Monthly 111 (2004) 157-159.
%H A. Mercer and P. Mercer, <a href="http://dx.doi.org/10.1155/S016117120000257X">Cauchy's interlace theorem and lower bounds for the spectral radius</a>, International Journal of Mathematics and Mathematical Sciences 23, no. 8 (2000) 563-566.
%e Top of the array:
%e 1...-1
%e 1...-18....1
%e 1...-84....116....-1
%e 1...-439...1221...-839...1
%t f[k_] := Fibonacci[k + 1]^2;
%t U[n_] := NestList[Most[Prepend[#, 0]] &, #, Length[#] - 1] &[Table[f[k], {k, 1, n}]];
%t L[n_] := Transpose[U[n]];
%t F[n_] := CharacteristicPolynomial[L[n].U[n], x];
%t c[n_] := CoefficientList[F[n], x]
%t TableForm[Flatten[Table[F[n], {n, 1, 10}]]]
%t Table[c[n], {n, 1, 12}]
%t Flatten[%]
%t TableForm[Table[c[n], {n, 1, 10}]]
%Y Cf. A203003, A202605.
%K tabl,sign
%O 1,4
%A _Clark Kimberling_, Dec 27 2011