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%I #9 Aug 30 2021 21:53:04
%S 1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,1,0,1,0,0,0,0,0,0,0,
%T 0,1,0,0,0,0,0,0,0,0,1,0,0,0,1,1,0,0,0,1,0,0,0,0,0,0,0,0,1,0,0,0,0,0,
%U 0,0,0,1,0,0,1,0,0,0,0,0,1,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,1,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,1,0,0,0,1
%N a(n) = 1 if the greatest prime factor of A000593(n) [sum of odd divisors of n] is at least as large as the greatest prime factor of n itself, otherwise a(n) = 0.
%H Antti Karttunen, <a href="/A347246/b347246.txt">Table of n, a(n) for n = 1..65537</a>
%H <a href="/index/Ch#char_fns">Index entries for characteristic functions</a>
%H <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>
%F a(n) = [A006530(A000593(n)) >= A006530(n)], where [ ] is the Iverson bracket.
%F For n > 1, a(n) = 1 iff A347245(n) = 1.
%o (PARI)
%o A006530(n) = if(1==n, n, my(f=factor(n)); f[#f~, 1]);
%o A000265(n) = (n >> valuation(n, 2));
%o A000593(n) = sigma(A000265(n));
%o A347246(n) = (A006530(A000593(n))>=A006530(n));
%Y Characteristic function of A347247. A347248 gives the positions of zeros.
%Y Cf. A000593, A006530, A347244, A347245.
%Y Cf. also A336352.
%K nonn
%O 1
%A _Antti Karttunen_, Aug 28 2021
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