OFFSET
1,1
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..49
EXAMPLE
G.f.: A(x) = 2*x + 84*x^3 + 276892*x^5 + 111457917800*x^7 + ...
MATHEMATICA
Rest@With[{m=30}, CoefficientList[Series[Sum[ArcSinh[2^(2*j+1)*x]^(2*j+1)/(2*j+1)!, {j, 0, m+2}], {x, 0, m}], x]] (* G. C. Greubel, Mar 15 2021 *)
PROG
(PARI) {a(n)=polcoeff(sum(k=0, n\2, asinh(2^(2*k+1)*x +x*O(x^n))^(2*k+1)/(2*k+1)!), n)}
(Magma)
m:=30;
R<x>:=PowerSeriesRing(Rationals(), 30);
Coefficients(R!( (&+[Argsinh(2^(2*j+1)*x)^(2*j+1)/Factorial(2*j+1): j in [0..m+2]]) )); // G. C. Greubel, Mar 15 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Jan 10 2008
STATUS
approved