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A072751 Greatest of the most frequent prime factors of squarefree numbers <= n; a(1)=1. 4
1, 2, 3, 5, 3, 3, 2, 2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(n)=2 for n>14.

LINKS

Table of n, a(n) for n=1..105.

MATHEMATICA

max = 200; primeFactors = FactorInteger[#][[All, 1]]& /@ Select[Range[max], SquareFreeQ]; a[n_] := Sort[ Tally[ Take[ primeFactors, n] // Flatten], Which[#1[[2]] > #2[[2]], True, #1[[2]] == #2[[2]], #1[[1]] > #2[[1]], True, False]& ][[1, 1]]; Table[a[n], {n, 1, primeFactors // Length}] (* Jean-Fran├žois Alcover, Oct 14 2013 *)

CROSSREFS

Cf. A005117, A072747, A072748, A072749, A072750.

Sequence in context: A254862 A322235 A172984 * A251542 A131971 A321882

Adjacent sequences:  A072748 A072749 A072750 * A072752 A072753 A072754

KEYWORD

nonn,nice

AUTHOR

Reinhard Zumkeller, Jul 08 2002

STATUS

approved

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Last modified June 2 18:25 EDT 2020. Contains 334787 sequences. (Running on oeis4.)