A246299 - OEIS

%I #42 May 13 2023 11:55:26

%S 2,8,14,21,27,33,39,46,52,58,65,71,77,83,90,96,102,109,115,121,127,

%T 134,140,146,153,159,165,171,178,184,190,196,203,209,215,222,228,234,

%U 240,247,253,259,266,272,278,284,291,297,303,310,316,322,328,335,341

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

%C The sequences A026309, A246297, A246298, A246299 partition the nonnegative integers.

%C Numbers like 20, 64, 108, 152, 177, 221, 265, 309, ... are in none of these 4 sequences. - _R. J. Mathar_, May 18 2020

%H R. J. Mathar, <a href="/A246299/b246299.txt">Table of n, a(n) for n = 1..987</a>

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

%t Select[t, f[#] < f[# + 1] &]  (* A026309 *)

%t Select[t, f[#] > f[# + 1] < f[# + 2] &]  (* A246297 *)

%t Select[t, f[#] > f[# + 1] > f[# + 2] < f[# + 3] &]  (* A246298 *)

%t Select[t, f[#] > f[# + 1] > f[# + 2] > f[# + 3] < f[# + 4] &] (* A246299 *)

%t Position[Partition[Table[Sin[n],{n,400}],5,1],_?(#[[1]]>#[[2]]>#[[3]]>#[[4]]<#[[5]]&),1,Heads->False]//Flatten (* _Harvey P. Dale_, May 13 2023 *)

%Y Cf. A026309, A246297, A246298, A246293 (complement of A026309).

%K nonn,easy

%O 1,1

%A _Clark Kimberling_, Aug 21 2014

%E Corrected signs in NAME. - _R. J. Mathar_, May 18 2020