A120751 (v(1), u(1), v(2), u(2), v(3), u(3), ...), where u = A120243 and v = A120749.

2, 1, 4, 3, 7, 5, 9, 6, 11, 8, 12, 10, 14, 13, 16, 15, 19, 17, 21, 18, 23, 20, 24, 22, 26, 25, 28, 27, 31, 29, 33, 30, 36, 32, 38, 34, 40, 35, 41, 37, 43, 39, 45, 42, 48, 44, 50, 46, 52, 47, 53, 49, 55, 51, 57, 54, 60, 56, 62, 58, 64, 59, 65, 61, 67, 63, 69, 66, 70, 68, 72, 71

Offset: 1

Author

Clark Kimberling, Jul 01 2006

Keywords

• nonn

Comments

A permutation of the positive integers.

Links

• Clark Kimberling, Table of n, a(n) for n = 1..2000

Crossrefs

Cf. A120243, A120749, A120750.

Programs

Mathematica

z = 4100; r = Sqrt[2];
f[n_] := f[n] = If[FractionalPart[n*r] < 1/2, 0, 1]
u = Flatten[Position[Table[f[n], {n, 1, z}], 0]]; (* A120243 *)
v = Flatten[Position[Table[f[n], {n, 1, z}], 1]]; (* A120749 *)
w = Riffle[Take[v, z/4], Take[u, z/4]]; (* A120751 *)

Extensions

Updated by Clark Kimberling, Sep 16 2014