

A233246


Sum of squares of cycle lengths for different cycles in Fibonaccilike sequences modulo n.


1



1, 10, 65, 82, 417, 650, 769, 658, 1793, 4170, 1151, 3026, 4705, 7690, 7137, 5266, 10369, 7562, 6319, 19218, 6977, 11510, 25345, 12818, 52417, 47050, 48449, 35410, 11565, 71370, 28351, 42130, 39615, 41482, 81057, 30674, 103969, 25282, 80033
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,2


COMMENTS

Here Fibonaccilike means a sequence following the Fibonacci recursion: b(n)=b(n1)+b(n2). These sequences modulo n cycle. The number of different cycles is A015134(n).
This sequence divided by n^2 is the average cycle length per different starting pairs modulo n, see A233248.
If n is in A064414, then a(n)/n^2 is the average distance between two neighboring multiples of n.
If n is in A064414, then a(n)/2n^2 is the average distance to the next zero over all starting pairs of remainders.


LINKS



EXAMPLE

For n=4 there are four possible cycles: A trivial cycle of length 1: 0; two cycles of length 6: 0,1,1,2,3,1; and a cycle of length 3: 0,2,2. Hence, a(4)=1+9+36+36=82.


MATHEMATICA

cl[i_, j_, n_] := (step = 1; first = i; second = j;
next = Mod[first + second, n];
While[second != i  next != j, step++; first = second;
second = next; next = Mod[first + second, n]]; step)
Table[Total[
Flatten[Table[cl[i, j, n], {i, 0, n  1}, {j, 0, n  1}]]], {n, 50}]


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



