A086567 Length of cycle produced by the function f: (x; y; z) ->(x-y-z; y; 2*y + z) if y + = z <x and (x; y; z) ->(y + z -x; x; 2*x -z) if y +z >x when started at (n,1,1).

1, 0, 3, 5, 4, 0, 5, 10, 7, 11, 6, 0, 7, 16, 11, 9, 10, 21, 8, 0, 9, 21, 12, 27, 11, 14, 17, 23, 10, 0, 11, 32, 18, 27, 18, 13, 15, 28, 19, 32, 12, 0, 13, 38, 25, 19, 18, 47, 15, 44, 16, 38, 18, 50, 14, 0, 15, 39, 20, 59, 18, 54, 28, 17, 24, 31, 21, 28, 29, 49, 16, 0, 17

Offset

1,3

Links

Table of n, a(n) for n=1..73.

Formula

a(k^2 + k) = 0, a(k^2 + k - 1) = 2*k, a(k^2 + k + 1) = a(k^2) = 2*k + 1

Example

a(5) = 4 because (5; 1; 1) -> (3; 1; 3) -> (1; 3; 3) -> (5; 1; = -1) -> (5; 1; 1) : length of cycle =4.

Crossrefs

Cf. A087855.

Sequence in context: A096822 A195383 A303069 * A016611 A198619 A168223

Adjacent sequences: A086564 A086565 A086566 * A086568 A086569 A086570

Keyword

nonn

Author

Philippe Deléham, Sep 24 2003

Status

approved