OFFSET
1,2
COMMENTS
FORMULA
From Amiram Eldar, Jan 18 2022: (Start)
Equals 1 + Sum_{k>=1} (-1)^k*Fibonacci(k-1)/k!.
Equals exp(-1/2)*(1 + sqrt(5)/5 + 2/(exp(sqrt(5))-1))*sinh(sqrt(5)/2). (End)
EXAMPLE
1.39729651650004415809334932390899486052640...
MATHEMATICA
f[x_] := Exp[-x]; r[n_] := Fibonacci[n];
c[n_] := SeriesCoefficient[Series[f[x], {x, 0, n}], n]
u0 = N[Sum[c[n]*r[n - 1], {n, 0, 100}], 100]
RealDigits[u0, 10]
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Clark Kimberling, Jul 14 2011
STATUS
approved