A033852 - OEIS

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A033852

Integers k such that j(k)*phi(k) = sigma(k), where j(n) = A033831(n).

%I #20 Jul 20 2020 02:01:19

%S 35,105,248,418,594,744,812,1254

%N Integers k such that j(k)*phi(k) = sigma(k), where j(n) = A033831(n).

%C a(9) > 10^7. - _Michel Marcus_, Nov 05 2014

%C a(9) > 10^8. - _Manfred Scheucher_, May 30 2015

%o (PARI) isok(n) = sumdiv(n, d, (d>=3) && (q=n/d) && (q>=1) && (q<=d-2))*eulerphi(n) == sigma(n); \\ _Michel Marcus_, Nov 05 2014

%Y Cf. A000010 (phi), A000203 (sigma), A033831.

%K more,nonn

%O 1,1

%A _Naohiro Nomoto_