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Integers m such that A071324(m) = A206369(m).
4

%I #9 Mar 11 2020 06:11:36

%S 1,2,3,4,5,7,8,9,11,13,16,17,19,20,23,25,27,28,29,31,32,37,41,43,44,

%T 47,49,52,53,59,61,64,67,68,71,73,76,79,81,83,89,92,97,99,100,101,103,

%U 107,109,113,116,117,121,124,125,127,128,131,137,139,148,149,151,153,157

%N Integers m such that A071324(m) = A206369(m).

%C Powers of primes (A000961) are in this sequence.

%H Amiram Eldar, <a href="/A317923/b317923.txt">Table of n, a(n) for n = 1..10000</a>

%o (PARI) a071324(n) = my(d=Vecrev(divisors(n))); sum(k=1, #d, (-1)^(k+1)*d[k]);

%o a206369(n) = a(n) = sumdiv(n, d, eulerphi(n/d) * issquare(d));

%o isok(n) = a071324(n) == a206369(n);

%Y Cf. A000961, A071324, A206369, A317924 (a subsequence).

%K nonn

%O 1,2

%A _Michel Marcus_, Aug 11 2018