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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]. 2
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified August 9 02:14 EDT 2020. Contains 336310 sequences. (Running on oeis4.)