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exp(arcsinh(arctanh(x)))=1+x+1/2!*x^2+2/3!*x^3+5/4!*x^4+24/5!*x^5...
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%I #8 Dec 21 2013 22:37:14

%S 1,1,1,2,5,24,109,720,4521,40320,330681,3628800,36468717,479001600,

%T 5721101541,87178291200,1205289090513,20922789888000,328897528901361,

%U 6402373705728000,112769846051251797,2432902008176640000

%N exp(arcsinh(arctanh(x)))=1+x+1/2!*x^2+2/3!*x^3+5/4!*x^4+24/5!*x^5...

%F E.g.f.: Q(0)-1, where Q(k) = 2 + arctanh(x)/(1 - arctanh(x)/Q(k+1) ); (continued fraction). - _Sergei N. Gladkovskii_, Dec 19 2013

%Y Bisections are A010050 and |A012091|.

%K nonn

%O 0,4

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