%I #2 May 11 2007 03:00:00
%S 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 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 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 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 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 a(n)=8*104767(n) if n != 1, a(1)=4.
%Y Cf. A104767.
%K easy,nonn
%O 0,1
%A Michele Dondi (blazar(AT)lcm.mi.infn.it), Mar 24 2005
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