The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 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 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified February 7 12:25 EST 2023. Contains 360116 sequences. (Running on oeis4.)