A246303 Numbers k such that cos(k) < cos(k+1).

3, 4, 5, 9, 10, 11, 12, 16, 17, 18, 22, 23, 24, 28, 29, 30, 35, 36, 37, 41, 42, 43, 47, 48, 49, 53, 54, 55, 56, 60, 61, 62, 66, 67, 68, 72, 73, 74, 79, 80, 81, 85, 86, 87, 91, 92, 93, 97, 98, 99, 100, 104, 105, 106, 110, 111, 112, 116, 117, 118, 123, 124

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..4000

Crossrefs

Cf. A026304, A246305, 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 *)