login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A193016
Decimal expansion of the coefficient of x in the reduction of sinh(x) by x^2->x+1.
2
1, 3, 7, 7, 6, 7, 5, 3, 2, 7, 4, 9, 0, 9, 4, 6, 5, 4, 6, 2, 1, 1, 5, 6, 5, 1, 2, 1, 0, 7, 0, 3, 9, 1, 7, 7, 3, 6, 9, 5, 8, 3, 5, 1, 5, 6, 0, 4, 1, 3, 1, 2, 2, 0, 0, 2, 6, 7, 3, 2, 1, 5, 9, 2, 5, 7, 6, 0, 2, 5, 7, 9, 2, 0, 9, 9, 3, 9, 1, 1, 3, 0, 2, 1, 8, 1, 0, 8, 8, 7, 7, 0, 5, 3, 3, 3, 0, 5, 3, 6
OFFSET
1,2
COMMENTS
Reduction of a function f(x) by a substitution q(x)->s(x) is introduced at A193010.
FORMULA
From Amiram Eldar, Jan 18 2022: (Start)
Equals Sum_{k>=0} Fibonacci(2*k+1)/(2*k+1)!.
Equals (e+1)*sinh(sqrt(5)/2)/sqrt(5*e). (End)
EXAMPLE
1.3776753274909465462115651210703917736958351560...
MATHEMATICA
f[x_] := Sinh[x]; r[n_] := Fibonacci[n];
c[n_] := SeriesCoefficient[Series[f[x], {x, 0, n}], n]
u1 = N[Sum[c[n]*r[n], {n, 0, 300}], 100]
RealDigits[u1, 10]
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Clark Kimberling, Jul 14 2011
STATUS
approved