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A073481 Least prime factor of the n-th squarefree number. 7
1, 2, 3, 5, 2, 7, 2, 11, 13, 2, 3, 17, 19, 3, 2, 23, 2, 29, 2, 31, 3, 2, 5, 37, 2, 3, 41, 2, 43, 2, 47, 3, 53, 5, 3, 2, 59, 61, 2, 5, 2, 67, 3, 2, 71, 73, 2, 7, 2, 79, 2, 83, 5, 2, 3, 89, 7, 3, 2, 5, 97, 101, 2, 103, 3, 2, 107, 109, 2, 3, 113, 2, 5, 2, 7, 2, 3, 127, 3, 2, 131, 7, 2, 137, 2, 139, 3, 2, 11, 5 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(n) = A020639(A005117(n)).

a(n) = A265668(n,1). - Reinhard Zumkeller, Dec 13 2015

LINKS

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

MATHEMATICA

a = Select[Range[300], SquareFreeQ[#]&]; Table[FactorInteger[a[[n]]][[1, 1]], {n, Length[a]}] (* Vladimir Joseph Stephan Orlovsky, Jan 30 2012 *)

PROG

(Haskell)

a073482 = a020639 . a005117  -- Reinhard Zumkeller, Feb 04 2012

CROSSREFS

Cf. A073482.

Cf. A005117, A020639, A265668.

Sequence in context: A201652 A272636 A066949 * A178094 A122556 A175723

Adjacent sequences:  A073478 A073479 A073480 * A073482 A073483 A073484

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Aug 03 2002

EXTENSIONS

More terms from Jason Earls, Aug 06 2002

STATUS

approved

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Last modified October 21 22:22 EDT 2018. Contains 316430 sequences. (Running on oeis4.)