A341814 a(n) = n/(Sum_{k=1..n} 1/phi(A341813(n)*k)).

1, 1, 3, 8, 2, 16, 24, 192, 108, 3, 48, 360, 117, 630, 16, 1920, 5440, 2880, 13680, 57600, 5376, 5760, 31680, 11264, 17600, 54912, 85536, 126720, 565488, 5987520, 6874560, 4257792, 274428, 332640, 776160, 2737152, 177408, 38016, 9240, 760320, 997920, 5821200, 498960, 38115, 49280

Offset

1,3

Links

Table of n, a(n) for n=1..45.

Wikipedia, Harmonic mean.

Prog

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

Crossrefs

Cf. A000010, A341811.

Sequence in context: A357597 A138714 A336054 * A038755 A245171 A011230

Adjacent sequences: A341811 A341812 A341813 * A341815 A341816 A341817

Keyword

nonn

Author

Seiichi Manyama, Feb 20 2021

Status

approved