A246294 Numbers k such that sin(k) < sin(k+1) > sin(k+2).

1, 7, 13, 19, 26, 32, 38, 45, 51, 57, 63, 70, 76, 82, 89, 95, 101, 107, 114, 120, 126, 133, 139, 145, 151, 158, 164, 170, 176, 183, 189, 195, 202, 208, 214, 220, 227, 233, 239, 246, 252, 258, 264, 271, 277, 283, 290, 296, 302, 308, 315, 321, 327, 334, 340

Offset: 1

Author

Clark Kimberling, Aug 21 2014

Keywords

• nonn
• easy

Comments

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

Numbers like 42, 86, 130, 199, 243, 287,.. are in none of these 4 sequences. - R. J. Mathar, May 18 2020

Links

• Clark Kimberling, Table of n, a(n) for n = 1..1000

Crossrefs

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

Programs

Mathematica

z = 500; f[x_] := f[x] = Sin[x]; t = Range[0, z];
Select[t, f[#] > f[# + 1] &]  (* A246293 *)
Select[t, f[#] < f[# + 1] > f[# + 2] &]  (* A246294 *)
Select[t, f[#] < f[# + 1] < f[# + 2] > f[# + 3] &]  (* A246295 *)
Select[t, f[#] < f[# + 1] < f[# + 2] < f[# + 3] > f[# + 4] &] (* A246296 *)
Position[Partition[Sin[Range[350]],3,1],?(#[[1]]<#[[2]]>#[[3]]&),1,Heads-> False]//Flatten (* _Harvey P. Dale, Aug 03 2017 *)