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Engel expansion of log(2).
3

%I #35 Apr 13 2018 11:17:10

%S 2,3,7,9,104,510,1413,2386,40447,87110,124975,1565154,1766158,2440919,

%T 2637001,9192874,24998746,73973182,88828340,432049320,470421590,

%U 477600793,3313014448,4571423959,28839435286,40818751774

%N Engel expansion of log(2).

%C See A006784 for the definition of Engel expansion.

%D F. Engel, Entwicklung der Zahlen nach Stammbruechen, Verhandlungen der 52. Versammlung deutscher Philologen und Schulmaenner in Marburg, 1913, pp. 190-191.

%H G. C. Greubel and T. D. Noe, <a href="/A059180/b059180.txt">Table of n, a(n) for n = 1..1000</a>[Terms 1 to 300 computed by T. D. Noe; Terms 301 to 1000 computed by G. C. Greubel, Dec 27 2016]

%H F. Engel, <a href="/A006784/a006784.pdf">Entwicklung der Zahlen nach Stammbruechen</a>, Verhandlungen der 52. Versammlung deutscher Philologen und Schulmaenner in Marburg, 1913, pp. 190-191. English translation by Georg Fischer, included with his permission.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/EngelExpansion.html">Engel Expansion</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/NaturalLogarithmof2.html">Natural Logarithm of 2</a>

%H P. Erdős and Jeffrey Shallit, <a href="http://www.numdam.org/item?id=JTNB_1991__3_1_43_0">New bounds on the length of finite Pierce and Engel series</a>, Sem. Theor. Nombres Bordeaux (2) 3 (1991), no. 1, 43-53.

%H <a href="/index/El#Engel">Index entries for sequences related to Engel expansions</a>

%t EngelExp[A_, n_] := Join[Array[1 &, Floor[A]], First@Transpose@

%t NestList[{Ceiling[1/Expand[#[[1]] #[[2]] - 1]], Expand[#[[1]] #[[2]] - 1]/1} &, {Ceiling[1/(A - Floor[A])], (A - Floor[A])/1}, n - 1]];

%t EngelExp[N[Log[2], 7!], 100] (* Modified by _G. C. Greubel_, Dec 27 2016 *)

%Y Cf. A002162 (decimal expansion of the natural logarithm of 2).

%K nonn,easy,nice

%O 1,1

%A _Mitch Harris_