|
| |
|
|
A137453
|
|
a(0) = 2, a(1) = 9; thereafter, a(n) = a(n-1)*a(n-2) mod (a(n-1)+a(n-2)).
|
|
1
|
|
|
|
2, 9, 7, 15, 17, 31, 47, 53, 91, 71, 143, 95, 19, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95, 95
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
0,1
|
|
|
COMMENTS
|
Playing around with different starting pairs, it looks like all starting pairs either end in a loop, or by going to the pair (0,0) which is either a loop or a singularity, depending on whether you take 0 mod 0 as being 0 or undefined. Furthermore, you can go an arbitrarily long time without looping. Take for large a: .., 6*a+6, 6*a, ... The next term is 6*a-6, and progressively it goes down the ladder by steps of 6 until it terminates at ..., 18, 12, 6, 0, 0. In a few minutes of searching, the longest sequence I could find which eventually loops without going to zero was the sequence starting with (29,574), which hits 855 at the 79th term and then stays at 855. - Jack Brennan
|
|
|
LINKS
|
|
|
|
EXAMPLE
|
2*9 mod 2+9 = 18 mod 11 = 7.
|
|
|
CROSSREFS
|
|
|
|
KEYWORD
|
nonn
|
|
|
AUTHOR
|
Eric Angelini, Jul 07 2008
|
|
|
EXTENSIONS
|
More terms from Jack Brennen, Jul 07 2008
|
|
|
STATUS
|
approved
|
| |
|
|
