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A321131 Values of m (mod 25), where A317905(m) = 1. Values of m (mod 25) such that V(m) = 1, where V(m) indicates the constant convergence speed of the tetration base m.

%I A321131 #24 Aug 23 2022 09:54:35
%S A321131 2,3,4,6,8,9,11,12,13,14,16,17,19,21,22,23
%N A321131 Values of m (mod 25), where A317905(m) = 1. Values of m (mod 25) such that V(m) = 1, where V(m) indicates the constant convergence speed of the tetration base m.
%C A321131 This sequence represents the values of the base a such that a^^m, where ^^ indicates tetration or hyper-4 (e.g., 3^^4=3^(3^(3^3))), is characterized by a unitary convergence speed.
%C A321131 64% of the positive integers belong to this list (see A317905).
%D A321131 Marco Ripà, La strana coda della serie n^n^...^n, Trento, UNI Service, Nov 2011. ISBN 978-88-6178-789-6
%H A321131 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 A321131 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 A321131 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 A321131 Wikipedia, <a href="https://en.wikipedia.org/wiki/Tetration">Tetration</a>
%e A321131 For m = 47, m (mod 25) == 22 and 22^^n has a unitary convergence speed, since A317905(m = 47) = 1 = A317905(m = 22).
%Y A321131 Cf. A067251, A317824, A317903, A317905, A321130.
%K A321131 nonn,fini,full
%O A321131 2,1
%A A321131 _Marco Ripà_, Oct 27 2018