A375911 - OEIS

%I #16 Sep 13 2024 08:00:21

%S 1,3,5,17,9,17,17,15,17,29,21,53,25,27,29,161,33,53,37,39,41,65,45,

%T 161,49,51,53,125,57,89,161,63,65,101,69,161,73,75,77,269,81,125,85,

%U 87,89,137,161,485,97,99,101,233,105,161,125,111,113,173,117,269,161

%N Largest value in the trajectory of 2*n - 1 in the Farkas map (A349407).

%H Paolo Xausa, <a href="/A375911/b375911.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = max{A350279(n,k) for 1 <= k <= A375909(n) + 1}.

%e a(10) = 29 because 29 is the largest value in the trajectory 19 -> 29 -> 15 -> 5 -> 3 -> 1.

%t FarkasStep[x_] := Which[Divisible[x, 3], x/3, Mod[x, 4] == 3, (3*x + 1)/2, True, (x + 1)/2];

%t Array[Max[FixedPointList[FarkasStep, 2*# - 1]] &, 100]

%Y Cf. A349407, A350279, A375909.

%Y Cf. A025586, A365478, A375280.

%K nonn,easy

%O 1,2

%A _Paolo Xausa_, Sep 02 2024