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A214897 Conway's subprime Fibonacci sequence: cycle lengths. 1
1, 10, 11, 18, 19, 56, 136 (list; graph; refs; listen; history; text; internal format)
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

Table of n, a(n) for n=1..7.

Richard K. Guy, Tanya Khovanova and Julian Salazar, Conway's subprime Fibonacci sequences, arXiv:1207.5099v1 [math.NT]

MATHEMATICA

see A214674

CROSSREFS

Cf. A000045, A020639, A175723, A214551, A014682, A214674, A214892-A214898.

Sequence in context: A112787 A264719 A214792 * A037307 A225079 A214790

Adjacent sequences:  A214894 A214895 A214896 * A214898 A214899 A214900

KEYWORD

nonn

AUTHOR

Wouter Meeussen, Jul 29 2012

STATUS

approved

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Last modified August 18 14:32 EDT 2017. Contains 290720 sequences.