|
%I #10 Jul 22 2023 17:40:32
%S 1,0,0,2,0,3,4,0,0,5,6,0,7,0,0,8,0,9,10,0,11,0,0,12,13,0,0,14,0,15,16,
%T 0,0,17,18,0,19,0,0,20,21,0,0,22,0,23,24,0,25,0,0,26,0,27,28,0,0,29,
%U 30,0,31,0,0,32,0,33,34,0,35,0,0,36,37,0,0,38,0,39,40,0,41,0,0,42,0,43,44,0
%N An evil count.
%C Counting numbers appear at positions indexed by the evil numbers A001969, 0 otherwise.
%H Amiram Eldar, <a href="/A102389/b102389.txt">Table of n, a(n) for n = 0..10000</a>
%F a(n) = (1+floor(n/2))*(1+(-1)^A000120(n))/2.
%F a(n) = (1+floor(n/2))(1+(-1)^A010060(n))/2.
%F A008619(n) = a(n) + A102390(n).
%t a[n_] := (1 + Floor[n/2])*(1 + (-1)^DigitCount[n, 2, 1])/2; Array[a, 100, 0] (* _Amiram Eldar_, Jul 22 2023 *)
%Y Cf. A000120, A001969, A008619, A010060, A102390.
%K easy,nonn,base
%O 0,4
%A _Paul Barry_, Jan 06 2005
|
