A246294 - OEIS

%I #12 May 18 2020 12:06:50

%S 1,7,13,19,26,32,38,45,51,57,63,70,76,82,89,95,101,107,114,120,126,

%T 133,139,145,151,158,164,170,176,183,189,195,202,208,214,220,227,233,

%U 239,246,252,258,264,271,277,283,290,296,302,308,315,321,327,334,340

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

%C The sequences A246293, A246294, A246295, A246296 partition the nonnegative integers.

%C Numbers like 42, 86, 130, 199, 243, 287,.. are in none of these 4 sequences. - _R. J. Mathar_, May 18 2020

%H Clark Kimberling, <a href="/A246294/b246294.txt">Table of n, a(n) for n = 1..1000</a>

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

%t Select[t, f[#] > f[# + 1] &]  (* A246293 *)

%t Select[t, f[#] < f[# + 1] > f[# + 2] &]  (* A246294 *)

%t Select[t, f[#] < f[# + 1] < f[# + 2] > f[# + 3] &]  (* A246295 *)

%t Select[t, f[#] < f[# + 1] < f[# + 2] < f[# + 3] > f[# + 4] &] (* A246296 *)

%t Position[Partition[Sin[Range[350]],3,1],_?(#[[1]]<#[[2]]>#[[3]]&),1,Heads-> False]//Flatten (* _Harvey P. Dale_, Aug 03 2017 *)

%Y Cf. A246293, A246295, A246296, A026309 (complement of A246293).

%K nonn,easy

%O 1,2

%A _Clark Kimberling_, Aug 21 2014