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
Wikipedia, Collatz conjecture
FORMULA
a(1) = -17, a(n+1) = -A123684(abs(a(n))).
a(n+11) = a(n).
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Joe Slater, Nov 07 2017
STATUS
approved