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Log of g.f. of numbers of preferential arrangements.
1

%I #25 Jan 05 2021 03:01:58

%S 1,0,2,4,34,196,1826,17172,199074,2510116,35862562,559572916,

%T 9577862306,177417693636,3546104002338,75961485384532,

%U 1737273637523362,42235881659123812,1087865420946370082,29589907884231535860,847576876148087333538,25501591020532799366404

%N Log of g.f. of numbers of preferential arrangements.

%H Vincenzo Librandi, <a href="/A006989/b006989.txt">Table of n, a(n) for n = 0..200</a>

%H R. G. Wilson v, <a href="/A006989/a006989.pdf">Letter to N. J. A. Sloane, Jan. 1993</a>

%F E.g.f: log(1 + integral(B)) where B is the e.g.f. for A000670.

%t CoefficientList[Series[2/((2 - E^x)*(2 + x - Log[2 - E^x])), {x, 0, 20}], x] * Range[0, 20]! (* _Vaclav Kotesovec_, Feb 24 2014 *)

%o (PARI) my(x='x+O('x^33)); Vec(serlaplace(log(1+intformal(1/(2-exp(x)))))) \\ _Joerg Arndt_, Jan 05 2021

%Y Cf. A000670.

%K nonn

%O 0,3

%A _N. J. A. Sloane_