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%I A360128 #10 Feb 21 2023 17:19:07
%S A360128 1,1,1,1,1,0,1,1,1,1,1,0,1,1,1,1,1,0,1,0,1,1,1,0,1,1,1,1,1,0,1,1,1,1,
%T A360128 1,0,1,1,1,0,1,0,1,1,1,1,1,0,1,1,1,1,1,0,1,0,1,1,1,0,1,1,1,1,1,0,1,1,
%U A360128 1,1,1,0,1,1,1,1,1,0,1,0,1,1,1,0,1,1,1,1,1,0,1,1,1,1,1,0,1,1,1,0,1,0,1,1,1,1,1,0,1,0,1,0,1,0,1,1,1,1,1,0,1
%N A360128 a(n) = 1 if there are no divisors d>1 of n such that also d+1 is a divisor of n, otherwise 0.
%H A360128 Antti Karttunen, <a href="/A360128/b360128.txt">Table of n, a(n) for n = 1..100000</a>
%H A360128 <a href="/index/Ch#char_fns">Index entries for characteristic functions</a>
%F A360128 a(n) = [A088722(n) == 0], where [ ] is the Iverson bracket.
%F A360128 a(n) = [A129308(n) < 2] = [A328457(n) < 2].
%o A360128 (PARI) A360128(n) = !sumdiv(n,d,(d>1)&&!(n%(d+1)));
%Y A360128 Characteristic function of A088725.
%Y A360128 Cf. A088722, A129308, A328457, A360129.
%K A360128 nonn
%O A360128 1
%A A360128 _Antti Karttunen_, Feb 20 2023

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