This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A327137 #14 Jun 22 2021 01:06:30 %S A327137 7,10,13,16,29,32,35,38,51,54,57,60,73,76,79,82,95,98,101,104,117,120, %T A327137 123,126,139,142,145,148,161,164,167,170,183,186,189,192,205,208,211, %U A327137 214,227,230,233,236,249,252,255,258,271,274,277,280,293,296,299 %N A327137 Numbers k such that sin(2k) > sin(2k+2) > sin(2k+4) < sin(2k+6). %C A327137 The sequences A026317, A327136, A327137 partition the nonnegative integers. %H A327137 Clark Kimberling, <a href="/A327137/b327137.txt">Table of n, a(n) for n = 1..10000</a> %e A327137 (sin 2, sin 4, ...) = (0.9, -0.7, -0.2, 0.9, -0.5, ...) approximately, so that the differences, in sign, are - + + - + + - - + - - + ..., with "+" in places 2,3,5,6,... (A026317), "- +" starting in places 1,4,8,11,... (A327136), and "- - +" starting in places 7,10,13,16,... (A327137). %t A327137 z = 500; f[x_] := f[x] = Sin[2 x]; t = Range[1, z]; %t A327137 Select[t, f[#] < f[# + 1] &] (* A026317 *) %t A327137 Select[t, f[#] > f[# + 1] < f[# + 2] &] (* A327136 *) %t A327137 Select[t, f[#] > f[# + 1] > f[# + 2] < f[# + 3] &] (* A327137 *) %Y A327137 Cf. A026309, A246303, A026317. %K A327137 nonn,easy %O A327137 1,1 %A A327137 _Clark Kimberling_, Aug 23 2019