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A007948 Largest cubefree number dividing n. 15
1, 2, 3, 4, 5, 6, 7, 4, 9, 10, 11, 12, 13, 14, 15, 4, 17, 18, 19, 20, 21, 22, 23, 12, 25, 26, 9, 28, 29, 30, 31, 4, 33, 34, 35, 36, 37, 38, 39, 20, 41, 42, 43, 44, 45, 46, 47, 12, 49, 50, 51, 52, 53, 18, 55, 28, 57, 58, 59, 60, 61, 62, 63, 4, 65, 66, 67, 68, 69, 70, 71, 36, 73 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(n) = max{A212793(A027750(n,k)) * A027750(n,k): k=1..A000005(n)}. - Reinhard Zumkeller, May 27 2012

LINKS

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

H. Bottomley, Some Smarandache-type multiplicative functions.

F. Smarandache, Only Problems, Not Solutions!.

FORMULA

Multiplicative with a(p^e) = p^(min(e, 2)). - David W. Wilson, Aug 01 2001

a(n) = A071773(n)*A007947(n). - observed by Velin Yanev, Aug 20 2017, confirmed by Antti Karttunen, Nov 28 2017

a(n) = n / A062378(n) = n / A003557(A003557(n)). - Antti Karttunen, Nov 28 2017

MATHEMATICA

Table[Apply[Times, FactorInteger[n] /. {p_, e_} /; p > 0 :> p^Min[e, 2]], {n, 73}] (* Michael De Vlieger, Jul 18 2017 *)

PROG

(Haskell)

a007948 = last . filter ((== 1) . a212793) . a027750_row

-- Reinhard Zumkeller, May 27 2012, Jan 06 2012

(PARI) a(n) = my(f=factor(n)); for (i=1, #f~, f[i, 2] = min(f[i, 2], 2)); factorback(f); \\ Michel Marcus, Jun 09 2014

(Scheme, with memoization-macro definec) (definec (A007948 n) (if (= 1 n) n (* (expt (A020639 n) (min 2 (A067029 n))) (A007948 (A028234 n))))) ;; Antti Karttunen, Nov 28 2017

CROSSREFS

Cf. A003557, A004709, A007947, A058035, A062378, A027748, A124010, A197863.

Sequence in context: A272573 A083501 A007922 * A038389 A058223 A245355

Adjacent sequences:  A007945 A007946 A007947 * A007949 A007950 A007951

KEYWORD

nonn,mult

AUTHOR

R. Muller

EXTENSIONS

More terms from Henry Bottomley, Jun 18 2001

STATUS

approved

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Last modified December 18 05:36 EST 2017. Contains 296135 sequences.