A060584 - OEIS

%I #9 Jul 14 2024 13:24:20

%S 0,1,1,1,0,1,1,1,0,0,1,1,1,0,1,1,1,0,0,1,1,1,0,1,1,1,0,0,1,1,1,0,1,1,

%T 1,0,0,1,1,1,0,1,1,1,0,0,1,1,1,0,1,1,1,0,0,1,1,1,0,1,1,1,0,0,1,1,1,0,

%U 1,1,1,0,0,1,1,1,0,1,1,1,0,0,1,1,1,0,1,1,1,0,0,1,1,1,0,1,1,1,0,0,1,1,1,0,1

%N Compare ultimate and penultimate digits of n base 3, i.e., 0 if n mod 3 = floor(n/3) mod 3, 1 otherwise; also 0 if (n mod 9) is a multiple of 4, 1 otherwise.

%F a(n) = a(n-9) = A060585(n) mod 2.

%F G.f.: x(1+x+x^2)(1+x^4)/(1-x^9).

%F a(n) = signum((n mod 9) mod 4). - _Alois P. Heinz_, Jul 14 2024

%t PadRight[{},120,{0,1,1,1,0,1,1,1,0}] (* _Harvey P. Dale_, Feb 12 2022 *)

%K base,easy,nonn

%O 0,1

%A _Henry Bottomley_, Apr 04 2001