A329477 - OEIS

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.

%I #8 Dec 02 2019 13:59:37

%S 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,

%T 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,

%U 11,17,32,19,13,40,42,32,6,38,34,15,8,19,40,21,8,21

%N 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.

%e 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.

%Y Cf. A000041.

%K nonn

%O 1,3

%A _Ali Sada_, Nov 13 2019