login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A275167 Pisano periods of A275124. 0
20, 60, 60, 40, 40, 60, 60, 60, 120, 140, 80, 120, 60, 120, 120, 100, 220, 60, 40, 60, 260, 120, 420, 140, 100, 240, 120, 120, 180, 120, 120, 180, 380, 120, 300, 180, 280, 240, 80, 240, 660, 60, 120, 60, 500, 240, 780, 120, 540, 120, 420, 420, 80, 360, 300, 200, 240, 620, 140, 120, 220, 60, 240, 180, 440, 120, 120, 120, 180, 1140, 520, 120 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..72.

FORMULA

a(n) = A001175(A275124(n)).

EXAMPLE

A275124(1) = 55, and PisanoPeriod(55) = 20, etc.

PROG

(Javascript)

let bases = [],

    Fs = [],

    Ls = [],

    agrees = [],

    baselimit = 2000;

for (let base = 2; base <= baselimit; base++) {

    let fibs = [1 % base, 1 % base],

        lucas = [2 % base, 1 % base],

        repeatingf = false,

        repeatingl = false;

    while (!repeatingf) {

        fibs.push((fibs[fibs.length - 2] + fibs[fibs.length - 1]) % base);

        if (1 == fibs[fibs.length - 2] &&

            0 == fibs[fibs.length - 1])

            repeatingf = true;

    }

    while (!repeatingl) {

        lucas.push((lucas[lucas.length - 2] + lucas[lucas.length - 1]) % base);

        if ((lucas[0] == (lucas[lucas.length - 2] + lucas[lucas.length - 1]) % base) &&

            (lucas[1] == (lucas[lucas.length - 2] + 2 *lucas[lucas.length - 1]) % base))

            repeatingl = true;

    }

    Fs[base] = fibs.length;

    Ls[base] = lucas.length;

    if (fibs.length != lucas.length)

        bases.push(base);

    //console.log('F', fibs.join(', '), 'L:', lucas.join(', '));

}

for (let i = 1; i <= baselimit/5; i++) {

    if (!bases.includes(i * 5)) {

        agrees.push(Fs[i * 5]);

    }

}

console.log(agrees.join(', '));

CROSSREFS

Cf. A001175, A275124.

Sequence in context: A229536 A220013 A220046 * A163761 A154072 A078184

Adjacent sequences:  A275164 A275165 A275166 * A275168 A275169 A275170

KEYWORD

nonn

AUTHOR

Kathie Dart, Jul 18 2016

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy .

Last modified July 25 20:38 EDT 2017. Contains 289797 sequences.