Numbers k such that d(r,k) = d(s,k), where d(x,k) = k-th binary digit of x, r = {golden ratio}, s = {(golden ratio)/2}, and { } = fractional part.
(history;
published version)
FORMULA
a(n) = n*round(cos(2^(n-2)*Pi*(1/phi^2))^2) where phi = (1 + sqrt(5))/2 - golden ratio. - Aivaras Stankaitis, May 05 2018
or
x(1)=sin(Pi*(1/phi^2)/2)^2
x(n+1)=4*X(n)*(1-X(n))
a(n)=n*(1-round(x(n)))
Discussion
Sat May 05
08:14
Joerg Arndt: So, indeed incorrect. I'll revert this edit.
FORMULA
or
x(1)=sin(Pi*(1/phi^2)/2)^2
x(n+1)=4*X(n)*(1-X(n))
a(n)=n*(1-round(x(n))
Discussion
Sat May 05
06:45
Aivaras Stankaitis: Described formula generating integer sequence a(1)=1, a(2)=0, a(3)=3, a(4)=0, a(5)=5, a(6)=6, a(7)=7, a(8)=0, a(9)=9, a(10)=10, a(11)=0, ...
Discussion
Sat May 05
06:42
Joerg Arndt: Formula gives 1, 0, 3, 0, 5, 6, 7, 0, 9, 10, 0, 12, 0, 0, 15, 16, 0, 0, 19, 20, 21, 0, ...
FORMULA
a(n) = n*round(cos(2^(n-2)*Pi*(1/phi^2))^2) where phi = (1 + sqrt(5))/2 - golden ratio. - _Aivaras Stankaitis _, May 05 2018
Discussion
Sat May 05
06:02
Omar E. Pol: Corrected attribution format.
FORMULA
a(n)=n*round(cos(2^(n-2)*Pi*(1/phi^2))^2) where phi=(1 + sqrt(5))/2 - golden ratio.- Aivaras Stankaitis May 05 2018