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%I #14 Apr 23 2022 09:45:00
%S 0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,1,0,0,0,0,0,0,0,1,
%T 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,
%U 0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1
%N a(n) = 1 if the arithmetic derivative of n is of the form 4k+2, otherwise 0.
%H Antti Karttunen, <a href="/A353495/b353495.txt">Table of n, a(n) for n = 0..65537</a>
%H <a href="/index/Ch#char_fns">Index entries for characteristic functions</a>
%F a(n) = 1 iff A353493(n) = 2, otherwise 0.
%F For all n >= 1, a(n) >= A353477(n).
%e For n = 135, A003415(135) = 162, which leaves the remainder 2 when divided by 4, therefore a(135) = 1.
%o (PARI)
%o A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
%o A353495(n) = (2==(A003415(n)%4));
%Y Characteristic function of A327862.
%Y Cf. A003415, A353493.
%Y Cf. also A165560, A353494.
%Y Differs from A353477 for the first time at n=135, where A353495(135) = 1, while A353477(135) = 0.
%K nonn
%O 0
%A _Antti Karttunen_, Apr 22 2022