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a(n) = n/(Sum_{k=1..n} 1/phi(A341813(n)*k)).
1

%I #9 Feb 20 2021 23:10:54

%S 1,1,3,8,2,16,24,192,108,3,48,360,117,630,16,1920,5440,2880,13680,

%T 57600,5376,5760,31680,11264,17600,54912,85536,126720,565488,5987520,

%U 6874560,4257792,274428,332640,776160,2737152,177408,38016,9240,760320,997920,5821200,498960,38115,49280

%N a(n) = n/(Sum_{k=1..n} 1/phi(A341813(n)*k)).

%H Wikipedia, <a href="http://www.wikipedia.org/wiki/Harmonic_mean">Harmonic mean</a>.

%o (PARI) a(n) = my(k=1); while (denominator(m=n/sum(j=1, n, 1/eulerphi(k*j))) != 1, k++); m;

%Y Cf. A000010, A341811.

%K nonn

%O 1,3

%A _Seiichi Manyama_, Feb 20 2021