Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
%I #8 Oct 07 2023 23:52:39
%S 0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,1,0,1,0,0,0,0,0,0,1,0,0,0,0,0,0,0,
%T 0,1,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,1,0,0,0,0,0,1,0,0,1,0,0,0,0,0,
%U 0,0,0,1,0,0,0,0,0,0,0,1,1,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,1
%N a(n) = 1 if A365711(n) is zero, 0 otherwise.
%H Antti Karttunen, <a href="/A366289/b366289.txt">Table of n, a(n) for n = 1..100000</a>
%H <a href="/index/Ch#char_fns">Index entries for characteristic functions</a>
%o (PARI)
%o A117966(n) = subst(Pol(apply(x->if(x == 2, -1, x), digits(n, 3)), 'x), 'x, 3); \\ From A117966
%o memoA365711 = Map();
%o A365711(n) = if(1==n,1,my(v); if(mapisdefined(memoA365711,n,&v), v, v = -sumdiv(n,d,if(d<n,A117966(n/d)*A365711(d),0)); mapput(memoA365711,n,v); (v)));
%o A366289(n) = !A365711(n);
%Y Characteristic function of A366290.
%Y Cf. A117966, A365711.
%K nonn
%O 1
%A _Antti Karttunen_, Oct 07 2023