A246305 Numbers k such that cos(k) > cos(k+1) > cos(k+2) < cos(k+3).

1, 7, 14, 20, 26, 33, 39, 45, 51, 58, 64, 70, 77, 83, 89, 95, 102, 108, 114, 121, 127, 133, 139, 146, 152, 158, 165, 171, 177, 183, 190, 196, 202, 208, 215, 221, 227, 234, 240, 246, 252, 259, 265, 271, 278, 284, 290, 296, 303, 309, 315, 322, 328, 334, 340

Offset: 1

Author

Clark Kimberling, Aug 22 2014

Keywords

• nonn
• easy

Comments

The sequences A246303, A246304, A246305, A246306 partition the nonnegative integers.

Links

• Clark Kimberling, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A026303, A246304, A246306, A026311 (complement of A246303).

Programs

Mathematica

z = 500; f[x_] := f[x] = Cos[x]; t = Range[0, z];
Select[t, f[#] < f[# + 1] &]  (* A246303 *)
Select[t, f[#] > f[# + 1] < f[# + 2] &]  (* A246304 *)
Select[t, f[#] > f[# + 1] > f[# + 2] < f[# + 3] &]  (* A246305 *)
Select[t, f[#] > f[# + 1] > f[# + 2] > f[# + 3] < f[# + 4] &] (* A246306 *)

Extensions

Definition corrected by Georg Fischer, Apr 01 2024