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A190818 E.g.f: 1/(1-2*tanh(x)) 2
1, 2, 8, 44, 320, 2912, 31808, 405344, 5903360, 96722432, 1760811008, 35260703744, 770296217600, 18229999665152, 464622502289408, 12687528814751744, 369557965317079040, 11437129322496131072, 374778854976227115008 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..100

FORMULA

E.g.f: 1/(1-2*tanh(x))

a(n) ~ n! * 2^(n+2)/(3*(log(3))^(n+1)). - Vaclav Kotesovec, Jun 26 2013

MAPLE

E(x):=1/(1-2*tanh(x)):

a[0]:=E(x):

for n from 1 to 30 do a[n]:=diff(a[n-1], x) od:

x:=0:

seq(a[n], n=0..30);

MATHEMATICA

CoefficientList[Series[1/(1-2*Tanh[x]), {x, 0, 20}], x]* Range[0, 20]! (* Vaclav Kotesovec, Jun 26 2013 *)

PROG

(PARI) x='x+O('x^66); /* that many terms */

Vec(serlaplace(1/(1-2*tanh(x)))) /* show terms */ /* Joerg Arndt, May 21 2011 */

CROSSREFS

Sequence in context: A123307 A293905 A244430 * A253949 A126101 A157994

Adjacent sequences:  A190815 A190816 A190817 * A190819 A190820 A190821

KEYWORD

nonn

AUTHOR

Miklos Kristof, May 21 2011

STATUS

approved

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Last modified May 21 15:32 EDT 2019. Contains 323444 sequences. (Running on oeis4.)