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].

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, 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, 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

Offset

0,1

Comments

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.

Links

Table of n, a(n) for n=0..100.

Formula

a(n)=8*104767(n) if n != 1, a(1)=4.

Crossrefs

Cf. A104767.

Sequence in context: A096616 A151558 A103613 * A199430 A228497 A199285

Adjacent sequences: A104765 A104766 A104767 * A104769 A104770 A104771

Keyword

easy,nonn

Author

Michele Dondi (blazar(AT)lcm.mi.infn.it), Mar 24 2005

Status

approved