A064558 a(n) = A064553(A064553(n)).

1, 2, 3, 4, 4, 6, 4, 8, 9, 8, 6, 12, 5, 8, 12, 16, 8, 18, 9, 16, 12, 12, 8, 24, 16, 10, 27, 16, 6, 24, 12, 32, 18, 16, 16, 36, 7, 18, 15, 32, 10, 24, 12, 24, 36, 16, 16, 48, 16, 32, 24, 20, 8, 54, 24, 32, 27, 12, 18, 48, 9, 24, 36, 64, 20, 36, 16, 32, 24, 32, 15, 72, 12, 14, 48, 36

Offset

1,2

Links

Table of n, a(n) for n=1..76.

Mathematica

b[n_] := Product[{p, e} = pe; (PrimePi[p] + 1)^e, {pe, FactorInteger[n]}];
a[n_] := b[b[n]];
Array[a, 100] (* Jean-François Alcover, Nov 21 2021 *)

Crossrefs

Sequence in context: A036804 A180046 A008329 * A178031 A008328 A298933

Adjacent sequences: A064555 A064556 A064557 * A064559 A064560 A064561

Keyword

mult,nonn

Author

Reinhard Zumkeller, Sep 21 2001

Status

approved