OFFSET
0,2
COMMENTS
LINKS
Eric Angelini, Divide by 2 or add the biggest anagram, math-fun discussion list, Mar 20 2022
FORMULA
a(n) = 0 iff n is in A352540.
EXAMPLE
The trajectory of n = 4 is 4 -> 8 -> 16 -> 8 -> 16 -> .... The value 8 is the first one to appear for a second time after the third iteration, therefore a(4) = 3.
a(8) = 4 because the trajectory of 8 is 8 -> 4 -> 2 -> 1 -> 2 -> 1 ..., so the number 2 is the first one to appear for a second time, after the 4th iteration of the map A352544.
The trajectory of n = 49 is (49, 143, 574, 287, 1159, 10670, 5335, 10868, 5434, 2717, 10438, 5219, 14740, 7370, 3685, 12338, 6169, 15830, 7915, 17666, 8833, 17666, 8833, ...): The number 17666 is the first one to appear for a second time, after the (a(49) = 21)-st iteration.
PROG
CROSSREFS
KEYWORD
nonn,base
AUTHOR
M. F. Hasler, Mar 20 2022
STATUS
approved