

A081169


Triangle in which nth row gives trajectory of n (including n itself) under the map x > x/2 if x is even, x > 3*x1 if x is odd, stopping when reaching 1, 5 or 17.


0



1, 2, 1, 2, 1, 3, 8, 4, 2, 1, 4, 2, 1, 5, 14, 7, 20, 10, 5, 6, 3, 8, 4, 2, 1, 7, 20, 10, 5, 8, 4, 2, 1, 9, 26, 13, 38, 19, 56, 28, 14, 7, 20, 10, 5, 10, 5, 11, 32, 16, 8, 4, 2, 1, 12, 6, 3, 8, 4, 2, 1, 13, 38, 19, 56, 28, 14, 7, 20, 10, 5, 14, 7, 20, 10, 5, 15, 44, 22, 11, 32, 16, 8, 4, 2, 1, 16
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OFFSET

1,2


COMMENTS

It is conjectured that the sequence will always end in one of three loops: 1, 2,1,1, ...; 5 14 7 20 10 5...; or 17 50 25 74 37 110 55 164 82 41 122 61 182 91 272 136 68 34 17...


LINKS

Table of n, a(n) for n=1..87.


PROG

(PARI) xnm3(n) = { print1(1" "2" "1" "); for(x=2, n, x1=x; print1(x1" "); while(x1>1, if(x1%2==0, x1/=2, x1 = 3*p1); print1(x1" "); if(x1==5  x1==17, break); ) ) }


CROSSREFS

Cf. A080825.
Sequence in context: A137752 A331917 A328318 * A225765 A300588 A030359
Adjacent sequences: A081166 A081167 A081168 * A081170 A081171 A081172


KEYWORD

easy,nonn,tabf


AUTHOR

Cino Hilliard, Apr 16 2003


STATUS

approved



