%I #46 Sep 07 2022 10:27:57

%S 15,25,55,57,65,68,95,105,124,126,135,145,175,182,185,193,215,225,249,

%T 255,265,295,305,318,335,345,374,375,376,385,415,425,432,455,465,495,

%U 505,535,545,568,575,585,615,624,625,626,655,665,682,695,705,735,745

%N Tetration bases with a constant convergence speed >= 3.

%C The convergence speed of any integer greater than 1 and not divisible by 10 is constant if and only if we are considering an integer tetration and its constant convergence speed is greater than 2 if and only if the tetration base is of the form m + k*1000, for k >= 0, where m is a term.

%H Marco Ripà, <a href="/A354959/b354959.txt">Table of n, a(n) for n = 1..10000</a>

%H Marco Ripà, <a href="https://doi.org/10.7546/nntdm.2020.26.3.245-260">On the constant congruence speed of tetration</a>, Notes on Number Theory and Discrete Mathematics, Volume 26, 2020, Number 3, pp. 245—260.

%H Marco Ripà, <a href="https://doi.org/10.7546/nntdm.2021.27.4.43-61">The congruence speed formula</a>, Notes on Number Theory and Discrete Mathematics, 2021, 27(4), 43-61.

%H Marco Ripà and Luca Onnis, <a href="https://doi.org/10.7546/nntdm.2022.28.3.441-457">Number of stable digits of any integer tetration</a>, Notes on Number Theory and Discrete Mathematics, 2022, 28(3), 441-457.

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Tetration">Tetration</a>

%e 57 is a term since the constant convergence speed of 57 is 3 and (trivially) 57 has no trailing zeros.

%Y Cf. A317905, A337392, A337833, A321130, A321131.

%K nonn,base

%O 1,1

%A _Marco Ripà_, Jul 23 2022