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 A246305 #8 Apr 01 2024 10:20:32 %S A246305 1,7,14,20,26,33,39,45,51,58,64,70,77,83,89,95,102,108,114,121,127, %T A246305 133,139,146,152,158,165,171,177,183,190,196,202,208,215,221,227,234, %U A246305 240,246,252,259,265,271,278,284,290,296,303,309,315,322,328,334,340 %N A246305 Numbers k such that cos(k) > cos(k+1) > cos(k+2) < cos(k+3). %C A246305 The sequences A246303, A246304, A246305, A246306 partition the nonnegative integers. %H A246305 Clark Kimberling, <a href="/A246305/b246305.txt">Table of n, a(n) for n = 1..1000</a> %t A246305 z = 500; f[x_] := f[x] = Cos[x]; t = Range[0, z]; %t A246305 Select[t, f[#] < f[# + 1] &] (* A246303 *) %t A246305 Select[t, f[#] > f[# + 1] < f[# + 2] &] (* A246304 *) %t A246305 Select[t, f[#] > f[# + 1] > f[# + 2] < f[# + 3] &] (* A246305 *) %t A246305 Select[t, f[#] > f[# + 1] > f[# + 2] > f[# + 3] < f[# + 4] &] (* A246306 *) %Y A246305 Cf. A026303, A246304, A246306, A026311 (complement of A246303). %K A246305 nonn,easy %O A246305 1,2 %A A246305 _Clark Kimberling_, Aug 22 2014 %E A246305 Definition corrected by _Georg Fischer_, Apr 01 2024