A246306 Numbers k such that cos(k) > cos(k+1) > cos(k+2) > cos(k+3) < cos(k+4).

0, 6, 13, 19, 25, 32, 38, 44, 50, 57, 63, 69, 76, 82, 88, 94, 101, 107, 113, 120, 126, 132, 138, 145, 151, 157, 164, 170, 176, 182, 189, 195, 201, 207, 214, 220, 226, 233, 239, 245, 251, 258, 264, 270, 277, 283, 289, 295, 302, 308, 314, 321, 327, 333, 339

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, A246305, 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