A157104 - OEIS

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A157104

Arithmetic derivative of cubefree numbers.

0, 1, 1, 4, 1, 5, 1, 6, 7, 1, 16, 1, 9, 8, 1, 21, 1, 24, 10, 13, 1, 10, 15, 32, 1, 31, 1, 14, 19, 12, 60, 1, 21, 16, 1, 41, 1, 48, 39, 25, 1, 14, 45, 20, 56, 1, 16, 22, 31, 1, 92, 1, 33, 51, 18, 61, 1, 72, 26, 59, 1, 1, 39, 55, 80, 18, 71, 1, 43, 1, 124, 22, 45, 32, 1, 123, 20, 96, 34, 49

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,4

COMMENTS

a(n) = A003415(A004709(n)).

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

MATHEMATICA

Reap[Do[f = FactorInteger[n]; If[n == 1, Sow[0], If[And @@ (# <= 2 & ) /@ f[[All, 2]], Sow[Total[n*(f[[All, 2]]/f[[All, 1]])]]]], {n, 1, 100}]][[2, 1]] (* Jean-François Alcover, May 16 2013 *)

PROG

(Haskell)

a157104 = a003415 . a004709 -- Reinhard Zumkeller, May 24 2013

CROSSREFS

Cf. A068328, A068720.

Sequence in context: A357311 A373364 A107463 * A101322 A029644 A345305

Adjacent sequences: A157101 A157102 A157103 * A157105 A157106 A157107

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Feb 23 2009

STATUS

approved