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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
OFFSET
1,4
COMMENTS
a(n) = A003415(A004709(n)).
LINKS
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
Sequence in context: A357311 A373364 A107463 * A101322 A029644 A345305
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Feb 23 2009
STATUS
approved