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A294689
Collatz cycle of negative numbers starting with -17.
0
-17, -25, -37, -55, -82, -41, -61, -91, -136, -68, -34, -17, -25, -37, -55, -82, -41, -61, -91, -136, -68, -34, -17, -25, -37, -55, -82, -41, -61, -91, -136, -68, -34, -17, -25, -37, -55, -82, -41, -61, -91, -136, -68, -34
OFFSET
1,1
COMMENTS
This is the longest of the three known cycles of negative numbers under the reduced Collatz transformation x: x=x/2 when x is even, and x=(3x+1)/2 when x is odd. The other two cycles of negative numbers are (-1,-1,-1,...) and (-5,-7,-10,-5,-7,-10,...). Only one cycle of positive numbers is known: (1,2,1,2,...). (0,0,0,...) is also a cycle.
LINKS
Eric Weisstein's World of Mathematics, Collatz Problem
FORMULA
a(1) = -17, a(n+1) = -A123684(abs(a(n))).
a(n+11) = a(n).
CROSSREFS
Positive number transforms are in A014682; the absolute value of negative number transforms can be found in A123684.
Sequence in context: A140609 A131275 A227238 * A263540 A355769 A183346
KEYWORD
sign,easy
AUTHOR
Joe Slater, Nov 07 2017
STATUS
approved