A246443 - OEIS

%I #6 Sep 01 2014 18:50:57

%S 0,1,3,4,6,7,9,10,12,13,14,15,16,17,18,19,20,21,22,23,25,26,28,29,31,

%T 32,34,35,36,37,38,39,40,41,42,43,44,45,47,48,50,51,53,54,56,57,58,59,

%U 60,61,62,63,64,65,66,67,69,70,72,73,75,76,78,79,80,81

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

%H Clark Kimberling, <a href="/A246443/b246443.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. A246442 (complement of A246442), A246451.

%K nonn,easy

%O 1,3

%A _Clark Kimberling_, Aug 26 2014