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%I #8 Apr 22 2022 18:14:02
%S 1,1,1,0,1,0,1,0,0,1,1,0,1,0,1,0,1,1,1,0,0,0,1,0,1,1,1,0,1,0,1,0,0,1,
%T 0,0,1,0,1,0,1,1,1,0,0,0,1,0,0,1,1,0,1,0,0,0,0,1,1,0,1,0,1,0,1,1,1,0,
%U 0,0,1,0,1,1,1,0,0,0,1,0,0,1,1,0,1,0,1,0,1,1,1,0,0,0,0,0,1,1,1,0,1,0,1,0,0,1,1,0,1,0,1,0,1,1,0,0,0,0,1,0
%N a(1) = 1, and for n > 1, a(n) = 1 if the largest proper divisor of n is of the form 4k+1, otherwise 0.
%H Antti Karttunen, <a href="/A353491/b353491.txt">Table of n, a(n) for n = 1..65537</a>
%H <a href="/index/Ch#char_fns">Index entries for characteristic functions</a>
%F a(n) = 1 iff A353490(n) = 1, otherwise 0.
%o (PARI)
%o A032742(n) = if(1==n,n,n/vecmin(factor(n)[,1]));
%o A353491(n) = (1==(A032742(n)%4));
%Y Cf. A032742, A353490, A353492.
%K nonn
%O 1
%A _Antti Karttunen_, Apr 22 2022