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a(n) = A000960(n) mod 3.
0

%I #10 Aug 17 2017 02:56:29

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

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

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

%N a(n) = A000960(n) mod 3.

%C No 2's appear.

%p S[1]:={seq(i,i=1..10000)}: for n from 2 to 10000 do S[n]:=S[n-1] minus {seq(S[n-1][n*i],i=1..nops(S[n-1])/n)} od: A:=S[10000]: seq(A[j] mod 3,j=1..nops(A)); # _Emeric Deutsch_, Nov 15 2004

%t del[lst_, k_] := lst[[ Select[ Range[ Length[ lst]], Mod[ #, k] != 0 &]]]; For[ k = 2; s = Range[10000], k <= Length[s], k++, s = del[s, k]]; Mod[s, 3]

%Y Cf. A000960.

%K nonn,easy

%O 0,1

%A _N. J. A. Sloane_ and _David Applegate_, Nov 15 2004

%E More terms from _Robert G. Wilson v_ and _Emeric Deutsch_, Nov 15 2004