A063257 Let f be a function on rationals p/q (p,q coprime) defined by f(p/q) = abs(p-q)/g(p), where g(p) is the next odd number (starting with p) that we get after iteration of h(n) = n/2 when n is even, 5n+1 when n is odd. Start with f(n/1) and iterate f until it reaches again an integer, which is a(n). If no integer is reached, then a(n)=0.

0, 1, 2, 3, 9, 11, 1, 7, 15, 19, 2, 1, 7, 9, 11, 15, 27, 35, 6, 3, 7, 1, 5, 19, 13, 17, 19, 2, 21, 17, 2, 31, 51, 67, 19, 17, 13, 11, 1, 17, 45, 6, 11, 5, 79, 5, 5, 15, 25, 33, 50, 38, 8, 2, 9, 7, 5, 12, 45, 5, 1, 85, 40, 63, 99, 131, 15, 69, 7, 17, 13, 13, 3, 5, 7, 21, 67, 1, 1, 17, 9

Offset

1,3

Links

Table of n, a(n) for n=1..81.

Example

We get 6/1 -> 5/3 -> 2/13 -> 11/1 so a(6)=11.

Crossrefs

Cf. A062366, A063256, A063268.

Sequence in context: A057234 A109636 A057236 * A229492 A328970 A103039

Adjacent sequences: A063254 A063255 A063256 * A063258 A063259 A063260

Keyword

nonn

Author

Floor van Lamoen, Jul 12 2001

Status

approved