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 A104768 #2 May 11 2007 03:00:00 %S A104768 8,4,0,8,0,0,8,0,8,0,8,0,0,0,0,16,0,0,8,0,0,16,0,0,8,0,0,0,8,0,0,0,0, %T A104768 8,0,16,8,0,0,8,0,0,0,0,0,16,8,0,8,0,0,0,0,8,0,16,0,8,0,0,0,0,8,8,0,0, %U A104768 16,0,0,0,0,0,0,0,0,0,0,0,16,0,16,8,8,0,8,0,0,0,0,0,16,8,0,0,0,0,0,0,0,8,0 %N A104768 Number of matrices G with entries in Z satisfying G^2=G+1 and having the form 2G=[1+p q-2n | q+2n 1-p]. %C A104768 The matrix solutions to G^2=G+1 are gI, g'I (where g is the golden number and g'=1-g) and the matrices 2G=[1+p q-B | q+B 1-p]. It is easy to see that B must be even. %F A104768 a(n)=8*104767(n) if n != 1, a(1)=4. %Y A104768 Cf. A104767. %K A104768 easy,nonn %O A104768 0,1 %A A104768 Michele Dondi (blazar(AT)lcm.mi.infn.it), Mar 24 2005