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%I #9 Jun 30 2021 19:47:41
%S 1,1,1,2,1,2,1,2,1,2,1,4,1,2,1,3,1,3,1,2,1,2,1,5,1,2,2,3,1,4,1,3,1,2,
%T 1,6,1,2,1,4,1,3,1,1,2,2,1,7,1,2,2,3,1,4,1,4,1,2,1,7,1,2,1,4,2,4,1,2,
%U 1,3,1,8,1,2,2,3,1,3,1,1,2,2,1,7,1,2,1,4,1,6,1,2,1,2,1,8,1,3,2,4,1,4,1,1,2
%N Number of divisors d of n for which A342915(d) = A342915(n), where A342915(n) = gcd(1+n, psi(n)).
%H Antti Karttunen, <a href="/A344773/b344773.txt">Table of n, a(n) for n = 1..65537</a>
%F a(n) = Sum_{d|n} [A342915(d) = A342915(n)], where [ ] is the Iverson bracket.
%F a(n) <= A344771(n).
%o (PARI)
%o A001615(n) = if(1==n,n, my(f=factor(n)); prod(i=1, #f~, f[i, 1]^f[i, 2] + f[i, 1]^(f[i, 2]-1))); \\ After code in A001615
%o A342915(n) = gcd(1+n,A001615(n));
%o A344773(n) = { my(x=A342915(n)); sumdiv(n,d,A342915(d)==x); };
%Y Cf. A001615, A342915, A344771.
%Y Cf. also A344774.
%K nonn
%O 1,4
%A _Antti Karttunen_, May 31 2021
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