A120750 (u(1), v(1), u(2), v(2), u(3), v(3),...), where u = A120243 and v = A120749.

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

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, A120751.

Programs

Mathematica

z = 400; 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 *)
Riffle[Take[u, z/4], Take[v, z/4]] (* A120750 *)

Extensions

Updated by Clark Kimberling, Sep 16 2014