A069170 Values of phi(k)*Sum_{d|k} 1/phi(d) for nonprimes k.

1, 5, 6, 11, 10, 10, 15, 14, 15, 23, 20, 25, 21, 22, 33, 26, 26, 31, 35, 30, 47, 33, 34, 35, 50, 38, 39, 55, 42, 55, 50, 46, 69, 50, 52, 51, 65, 62, 55, 77, 57, 58, 75, 62, 70, 95, 65, 66, 85, 69, 70, 110, 74, 78, 95, 77, 78, 115, 94, 82, 105, 85, 86, 87, 121, 100, 91, 115

Offset

1,2

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Formula

a(n) = A069208(A018252(n)). - Amiram Eldar, Apr 29 2022

Mathematica

f[p_, e_] := (p^(e + 1) - p^e + p^(e - 1) - 1)/(p - 1); s[1] = 1; s[n_] := Times @@ f @@@ FactorInteger[n]; s /@ Select[Range[100], !PrimeQ[#] &] (* Amiram Eldar, Apr 29 2022 *)

Crossrefs

Cf. A000010, A018252, A069208.

Sequence in context: A119102 A162015 A162017 * A305293 A287265 A120517

Adjacent sequences: A069167 A069168 A069169 * A069171 A069172 A069173

Keyword

easy,nonn

Author

Benoit Cloitre, Apr 09 2002

Status

approved