OFFSET
0,3
COMMENTS
A347270 is related to the 3x + 1 (or Collatz) problem.
Conjectures from Alois P. Heinz, Aug 31 2021: (Start)
a(n) in {1, 2, 4, 5, 8, 10, 16, 26, 52, 53, 106, 155, 395, 425, 488, 668, 850, 866, 1732, 2308, 2429, 3644, 4858} for n >= 0.
a(n) in {1, 2, 4} for n >= 110. (End)
LINKS
MAPLE
b:= proc(n, k) option remember; `if`(k=0, n, (j->
`if`(j::even, j/2, 3*j+1))(b(n, k-1)))
end:
a:= n-> b(n+1, n):
seq(a(n), n=0..80); # Alois P. Heinz, Aug 25 2021
MATHEMATICA
b[n_, k_] := b[n, k] = If[k == 0, n, Function[j,
If[EvenQ[j], j/2, 3*j + 1]][b[n, k - 1]]];
a[n_] := b[n + 1, n];
Table[a[n], {n, 0, 80}] (* Jean-François Alcover, Apr 07 2022, after Alois P. Heinz *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Omar E. Pol, Aug 25 2021
STATUS
approved