A193035 Decimal expansion of the coefficient of x in the reduction of 2^(-x) by x^2->x+1.

5, 4, 0, 6, 8, 2, 6, 4, 1, 9, 5, 8, 4, 8, 0, 3, 8, 3, 7, 7, 7, 4, 1, 0, 5, 5, 2, 7, 2, 4, 2, 2, 1, 3, 0, 1, 2, 4, 8, 5, 3, 2, 6, 9, 1, 1, 1, 1, 6, 8, 3, 2, 4, 5, 8, 9, 2, 4, 2, 2, 0, 4, 6, 0, 0, 1, 1, 2, 4, 2, 6, 6, 3, 6, 2, 3, 0, 3, 2, 9, 8, 4, 8, 6, 1, 1, 9, 1, 3, 0, 5, 0, 8, 7, 2, 7, 3, 3, 7, 3

Offset

0,1

Comments

Reduction of a function f(x) by a substitution q(x)->s(x) is introduced at A193010.

Links

Table of n, a(n) for n=0..99.

Formula

From Amiram Eldar, Jan 19 2022: (Start)

Equals Sum_{k>=0} (-log(2))^k*Fibonacci(k)/k!.

Equals -(2^sqrt(5) - 1)/(sqrt(5)*2^phi), where phi is the golden ratio (A001622). (End)

Example

-0.540682641958480383777410552724221301248532691111...

Mathematica

f[x_] := 2^(-x); r[n_] := Fibonacci[n];
c[n_] := SeriesCoefficient[Series[f[x], {x, 0, n}], n]
u1 = N[Sum[c[n]*r[n], {n, 0, 100}], 100]
RealDigits[u1, 10]

Crossrefs

Cf. A000045, A001622, A193010, A192232, A193009.

Sequence in context: A197012 A200137 A197384 * A227966 A021653 A020847

Adjacent sequences: A193032 A193033 A193034 * A193036 A193037 A193038

Keyword

nonn,cons

Author

Clark Kimberling, Jul 14 2011

Status

approved