This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A110033 #5 Mar 30 2012 18:59:08 %S A110033 1,-1,1,1,-3,1,0,3,-8,1,0,0,9,-21,1,0,0,0,24,-55,1,0,0,0,0,64,-144,1, %T A110033 0,0,0,0,0,168,-377,1,0,0,0,0,0,0,441,-987,1,0,0,0,0,0,0,0,1155,-2584, %U A110033 1,0,0,0,0,0,0,0,0,3025,-6765,1,0,0,0,0,0,0,0,0,0,7920,-17711,1 %N A110033 A characteristic triangle for the Fibonacci numbers. %F A110033 Form the n X n Hankel matrices F(i+j-1), 1<=i, j<=n for the Fibonacci numbers and take the characteristic polynomials of these matrices. Triangle rows give coefficients of these characteristic polynomials. (Construction described by Michael Somos in A064831). Diagonal is (-1)^n*F(2n+2). Subdiagonal is A064831. Row sums are A110034. The unsigned matrix has row sums A110035. %e A110033 Rows begin %e A110033 1; %e A110033 -1,1; %e A110033 1,-3,1; %e A110033 0,3,-8,1; %e A110033 0,0,9,-21,1; %e A110033 0,0,0,24,-55,1; %e A110033 0,0,0,0,64,-144,1; %e A110033 0,0,0,0,0,168,-377,1; %K A110033 sign,tabl %O A110033 0,5 %A A110033 _Paul Barry_, Jul 08 2005