A353306 Numbers k such that 1 is in the transitive closure of the map x -> A353313(x) when starting iterating from x=k.

1, 3, 4, 9, 12, 27, 36, 81, 108, 193, 243, 324, 346, 436, 579, 729, 972, 1038, 1308, 1522, 1737, 1867, 2187, 2353, 2539, 2916, 3114, 3493, 3924, 4234, 4566, 5211, 5601, 5824, 6286, 6561, 7059, 7617, 8748, 9342, 9446, 9709, 10479, 10886, 11756, 11772, 12702, 13698, 13772, 14792, 14806, 15633, 15745, 16184, 16803, 17003

Offset: 1

Author

Antti Karttunen, Apr 13 2022

Keywords

• nonn

Crossrefs

Positions of ones in A353305.

Subsequences: A000244, A003946, A211221.

Programs

PARI

A353313(n) = { my(r=(n%3)); if(!r,n/3,((5*((n-r)/3)) + r + 3)); };
A353305(n) = { my(visited = Map(), m=0); for(j=1, oo, n = A353313(n); if(!m, m=n, m=min(m,n)); if(mapisdefined(visited, n), return(m), mapput(visited, n, j))); };
isA353306(n) = (1==A353305(n));