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Integers m, not powers of primes (A000961), such that A071324(m) = A206369(m).
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%I #9 Mar 11 2020 06:12:22

%S 20,28,44,52,68,76,92,99,100,116,117,124,148,153,164,171,172,188,196,

%T 207,212,236,244,261,268,272,279,284,292,304,316,332,333,356,368,369,

%U 387,388,404,412,423,428,436,452,464,477,484,496,500,508,524,531,548,549,556,592,596

%N Integers m, not powers of primes (A000961), such that A071324(m) = A206369(m).

%C For powers of primes x, we have A071324(x) = A206369(x), so this sequence lists the integers m that have the same property even though they are not powers of primes.

%H Amiram Eldar, <a href="/A317924/b317924.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) = sumdiv(n, d, eulerphi(n/d) * issquare(d));

%o isok(n) = (n!=1) && !isprimepower(n) && (a071324(n) == a206369(n));

%Y Cf. A000961, A071324, A206369.

%Y Intersection of A024619 and A317923.

%K nonn

%O 1,1

%A _Michel Marcus_, Aug 11 2018