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A157104 Arithmetic derivative of cubefree numbers. 1
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-Fran├žois Alcover, May 16 2013 *)

PROG

(Haskell)

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

CROSSREFS

Cf. A068328, A068720.

Sequence in context: A019303 A339967 A107463 * A101322 A029644 A024919

Adjacent sequences:  A157101 A157102 A157103 * A157105 A157106 A157107

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Feb 23 2009

STATUS

approved

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Last modified May 15 13:44 EDT 2021. Contains 343920 sequences. (Running on oeis4.)