login
A329477
a(n) is the number of iterations needed to reach 1 starting at n and using the map k -> (k/2 if k is even, otherwise k + (largest partition number < k)). Set a(n) = -1 if the trajectory never reaches 1.
0
0, 1, 5, 2, 4, 6, 8, 3, 5, 5, 7, 7, 9, 9, 11, 4, 6, 6, 8, 6, 8, 8, 27, 8, 14, 10, 14, 10, 31, 12, 41, 5, 33, 7, 39, 7, 16, 9, 20, 7, 22, 9, 29, 9, 26, 28, 13, 9, 13, 15, 30, 11, 32, 15, 28, 11, 17, 32, 19, 13, 40, 42, 32, 6, 38, 34, 15, 8, 19, 40, 21, 8, 21
OFFSET
1,3
EXAMPLE
The trajectory of 15 is [15, 26, 13, 24, 12, 6, 3, 5, 8, 4, 2, 1], taking 11 steps to reach 11. So a(15) = 11.
CROSSREFS
Cf. A000041.
Sequence in context: A308171 A376234 A265287 * A257701 A202494 A112597
KEYWORD
nonn
AUTHOR
Ali Sada, Nov 13 2019
STATUS
approved