A246388 Nonnegative integers k satisfying sin(k) >= 0 and sin(k+1) <= 0.

3, 9, 15, 21, 28, 34, 40, 47, 53, 59, 65, 72, 78, 84, 91, 97, 103, 109, 116, 122, 128, 135, 141, 147, 153, 160, 166, 172, 179, 185, 191, 197, 204, 210, 216, 223, 229, 235, 241, 248, 254, 260, 267, 273, 279, 285, 292, 298, 304, 311, 317, 323, 329, 336, 342

Offset: 0

Author

Clark Kimberling, Aug 24 2014

Keywords

• nonn
• easy

Comments

A246388 and A038130 (Beatty sequence for 2*Pi) partition A022844 (Beatty sequence for Pi). Likewise, A054386, the complement of A022844, is partitioned by A246389 and A246390. (See the Mathematica program.)

Links

• Clark Kimberling, Table of n, a(n) for n = 0..1000

Crossrefs

Cf. A022844, A038130, A054386, A246389, A246390.

Programs

Mathematica

z = 400; f[x_] := Sin[x]
Select[Range[0, z], f[#]*f[# + 1] <= 0 &] (* A022844 *)
Select[Range[0, z], f[#] >= 0 && f[# + 1] <= 0 &]  (* A246388 *)
Select[Range[0, z], f[#] <= 0 && f[# + 1] >= 0 &] (* A038130 *)
Select[Range[0, z], f[#]*f[# + 1] > 0 &] (* A054386 *)
Select[Range[0, z], f[#] >= 0 && f[# + 1] >= 0 &]  (* A246389 *)
Select[Range[0, z], f[#] <= 0 && f[# + 1] <= 0 &] (* A246390 *)