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 A013324 Numerator of [x^n] of the Taylor series arccosh(exp(x)-tanh(x))= x+x^2/2 -x^3/8 -7*x^4/48 +3*x^5/128 +631*x^6/11520 +37*x^7/15360 -12731*x^8/645120 -... 0

%I

%S 1,1,-1,-7,3,631,37,-12731,-37481,771163,590381,-195597517,-8025539,

%T -205204695149,5456117628779,3973785585851,-3056850228539,

%U -168086791499223239

%N Numerator of [x^n] of the Taylor series arccosh(exp(x)-tanh(x))= x+x^2/2 -x^3/8 -7*x^4/48 +3*x^5/128 +631*x^6/11520 +37*x^7/15360 -12731*x^8/645120 -...

%C The e.g.f. at x/2 seems to admit an integer representation: arccosh(exp(x)-tanh(x)) = 2*x/(2*1!) +4*x^2/(2^2*2!) -6*x^3/(2^3*3!) -56*x^4/(2^4*4!) +90*x^5/(2^5*5!) +2524*x^6/(2^6*6!) ...

%K sign,frac

%O 1,4

%A Patrick Demichel (patrick.demichel(AT)hp.com)

%E Values replaced by numerators. - R. J. Mathar, Dec 22 2011

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Last modified November 20 08:16 EST 2018. Contains 317385 sequences. (Running on oeis4.)