A246306 - OEIS

%I #8 Apr 01 2024 10:29:35

%S 0,6,13,19,25,32,38,44,50,57,63,69,76,82,88,94,101,107,113,120,126,

%T 132,138,145,151,157,164,170,176,182,189,195,201,207,214,220,226,233,

%U 239,245,251,258,264,270,277,283,289,295,302,308,314,321,327,333,339

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

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

%H Clark Kimberling, <a href="/A246306/b246306.txt">Table of n, a(n) for n = 1..1000</a>

%t z = 500; f[x_] := f[x] = Cos[x]; t = Range[0, z];

%t Select[t, f[#] < f[# + 1] &]  (* A246303 *)

%t Select[t, f[#] > f[# + 1] < f[# + 2] &]  (* A246304 *)

%t Select[t, f[#] > f[# + 1] > f[# + 2] < f[# + 3] &]  (* A246305 *)

%t Select[t, f[#] > f[# + 1] > f[# + 2] > f[# + 3] < f[# + 4] &] (* A246306 *)

%Y Cf. A026303, A246304, A246305, A026311 (complement of A246303).

%K nonn,easy

%O 1,2

%A _Clark Kimberling_, Aug 22 2014

%E Definition corrected by _Georg Fischer_, Apr 01 2024