Beatty Sequence

The Beatty sequence is a spectrum sequence with an irrational base. In other words, the Beatty sequence corresponding to an irrational number theta is given by |_theta_|, |_2theta_|, |_3theta_|, ..., where |_x_| is the floor function. If alpha and beta are positive irrational numbers such that

 1/alpha+1/beta=1,

then the Beatty sequences |_alpha_|, |_2alpha_|, ... and |_beta_|, |_2beta_|, ... together contain all the positive integers without repetition.

The sequences for particular values of alpha and beta are given in the following table (Sprague 1963; Wells 1986, pp. 35 and 40), where phi is the golden ratio.

parameterSloanesequence
alpha=sqrt(2)A0019511, 2, 4, 5, 7, 8, 9, 11, 12, ...
beta=2+sqrt(2)A0019523, 6, 10, 13, 17, 20, 23, 27, 30, ...
alpha=sqrt(3)A0228381, 3, 5, 6, 8, 10, 12, 13, 15, 17, ...
beta=1/2(3+sqrt(3))A0544062, 4, 7, 9, 11, 14, 16, 18, 21, 23, 26, ...
alpha=eA0228432, 5, 8, 10, 13, 16, 19, 21, 24, 27, 29, ...
beta=e/(e-1)A0543851, 3, 4, 6, 7, 9, 11, 12, 14, 15, 17, 18, ...
alpha=piA0228443, 6, 9, 12, 15, 18, 21, 25, 28, 31, 34, ...
beta=pi/(pi-1)A0543861, 2, 4, 5, 7, 8, 10, 11, 13, 14, 16, 17, 19, ...
alpha=phiA0002011, 3, 4, 6, 8, 9, 11, 12, 14, 16, 17, 19, 21, ...
beta=phi^2A0019502, 5, 7, 10, 13, 15, 18, 20, 23, 26, 28, 31, 34, ...

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