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Denominators of convergents to log_2 3.
(Formerly M1428)
15

%I M1428 #43 Sep 25 2023 14:41:48

%S 1,1,2,5,12,41,53,306,665,15601,31867,79335,111202,190537,10590737,

%T 10781274,53715833,171928773,225644606,397573379,6189245291,

%U 6586818670,65470613321,137528045312,753110839881,5409303924479,6162414764360

%N Denominators of convergents to log_2 3.

%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

%H T. D. Noe, <a href="/A005664/b005664.txt">Table of n, a(n) for n = 0..200</a>

%H Oliver K. Clay, <a href="https://doi.org/10.5642/jhummath.YQHO7207">The Long Search for Collatz Counterexamples</a>, J. Humanistic Math. (2023) Vol. 13, No. 2, 199-227. See p. 205.

%H R. E. Crandall, <a href="http://dx.doi.org/10.1090/S0025-5718-1978-0480321-3">On the 3x+1 problem</a>, Math. Comp., 32 (1978) 1281-1292.

%H E. G. Dunne, <a href="/DUNNE/TEMPERAMENT2.html">Pianos and Continued Fractions</a>

%H R. K. Guy, <a href="/A005663/a005663.pdf">Letter to N. J. A. Sloane, 1977</a>

%H David Ryan, <a href="http://arxiv.org/abs/1612.01860">An algorithm to assign musical prime commas to every prime number and construct a universal and compact free Just Intonation musical notation</a>, Preprint, arXiv preprint arXiv:1612.01860 [cs.SD], 2016.

%H Eric Weisstein's World of Music, <a href="http://www.ericweisstein.com/encyclopedias/music/CommaofPythagoras.html">Comma of Pythagoras</a>

%e log_2 3 = 1.5849625007211561814537389439...

%t Convergents[Log[2, 3], 30] // Denominator (* _Jean-François Alcover_, Dec 12 2016 *)

%o (PARI) a(n) = component(component(contfracpnqn(contfrac(log(3)/log(2), n)), 1), 2) \\ _Michel Marcus_, May 20 2013

%Y Cf. A005663, A028507, A020857.

%K nonn,frac,easy

%O 0,3

%A _N. J. A. Sloane_, _R. K. Guy_

%E More terms from _James A. Sellers_, Sep 16 2000