A343405 - OEIS

%I #20 Oct 01 2024 08:50:40

%S 0,1,5,6,11,12,17,18,23,24,29,36,65,72,101,108,137,144,173,209,210,

%T 419,420,629,630,839,840,1049,1050,1259,1260,1469,1470,1679,1680,1889,

%U 1890,2099,2100,2309,2939,4200,5670,7140,8609,10079,11340,12810,14280,15749

%N Numbers k such that A343404(k) = k.

%C If m belongs to this sequence, then the number obtained by removing the leading digit from the expansion of m in primary base also belongs to this sequence.

%C So the terms of the sequence can be mapped on a tree with root 0 (see illustration in Links section).

%C Is this sequence infinite?

%H Rémy Sigrist, <a href="/A343405/b343405.txt">Table of n, a(n) for n = 1..1000</a>

%H Rémy Sigrist, <a href="/A343405/a343405.png">Illustration of the terms < 2*3*5*7*11</a>

%H Rémy Sigrist, <a href="/A343405/a343405.gp.txt">PARI program for A343405</a>

%H <a href="/index/Pri#primorialbase">Index entries for sequences related to primorial base</a>

%e A343404(2099) = 2099, so 2099 belongs to this sequence.

%o (PARI) \\ See Links section.

%Y Cf. A266181, A319599, A343404.

%K nonn,base

%O 1,3

%A _Rémy Sigrist_, Apr 14 2021