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A214897
Conway's subprime Fibonacci sequence: cycle lengths.
2
1, 10, 11, 18, 19, 56, 136
OFFSET
1,2
COMMENTS
Similar to the Fibonacci recursion starting with a pair of positive integers, but each new nonprime term is divided by its least prime factor. The recursion enters a loop of length a(n) after a finite number of steps. Conjecture: the list of loops is complete (checked to [10^5, 10^5]), loops of length a(n) are unique and no infinite chains exist.
LINKS
Richard K. Guy, Tanya Khovanova and Julian Salazar, Conway's subprime Fibonacci sequences, arXiv:1207.5099v1 [math.NT]
MATHEMATICA
KEYWORD
nonn
AUTHOR
Wouter Meeussen, Jul 29 2012
STATUS
approved