login
Nonnegative integers k satisfying cos(k)*sin(k+1) < 0.
4

%I #5 Sep 01 2014 18:50:00

%S 2,5,8,11,24,27,30,33,46,49,52,55,68,71,74,77,90,93,96,99,112,115,118,

%T 121,134,137,140,143,156,159,162,165,178,181,184,187,200,203,206,209,

%U 222,225,228,231,244,247,250,253,266,269,272,275,288,291,294,297

%N Nonnegative integers k satisfying cos(k)*sin(k+1) < 0.

%H Clark Kimberling, <a href="/A246442/b246442.txt">Table of n, a(n) for n = 1..1000</a>

%t z = 420;

%t Select[Range[0, z], Cos[#] Sin[# + 1] < 0 &] (* A246442 *)

%t Select[Range[0, z], Cos[#] Sin[# + 1] > 0 &] (* A246443 *)

%Y Cf. A246443 (complement of A246442), A246450.

%K nonn,easy

%O 1,1

%A _Clark Kimberling_, Aug 26 2014