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A100376 a(n) is the largest number x such that for m=n to n+x-1, A006530(m) increases. 3
2, 1, 2, 1, 2, 1, 4, 3, 2, 1, 2, 1, 1, 1, 2, 1, 2, 1, 4, 3, 2, 1, 3, 2, 1, 3, 2, 1, 2, 1, 3, 2, 1, 1, 2, 1, 1, 1, 2, 1, 2, 1, 1, 3, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 4, 3, 2, 1, 2, 1, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 1, 2, 1, 3, 2, 1, 1, 3, 2, 1, 3, 2, 1, 1, 2, 1, 5, 4, 3, 2, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 1, 3 (list; graph; refs; listen; history; internal format)
OFFSET

2,1

COMMENTS

A006530(m) is the largest prime factor of m.

If p is an odd prime, a(p)=1, because the largest prime factor of p+1 is smaller than p.

EXAMPLE

a(8)=4 because the largest prime factors of 8,9,10,11 are 2,3,5,11; but A006530(12)=3.

MATHEMATICA

<<NumberTheory`NumberTheoryFunctions` mxp[x_] :=Max[PrimeFactorList[x]]; a[x_] := First[Flatten[Position[Sign[RotateLeft[Table[mxp[x+j], {j, 0, 10}]]-Table[mxp[x+j], {j, 0, 10}]], -1]]]; Table[a(w), {w, 1, 256}]

CROSSREFS

Cf. A006530, A070089, A071869, A100384, A100387.

Sequence in context: A161272 A160976 A029218 * A020738 A063279 A124333

Adjacent sequences:  A100373 A100374 A100375 * A100377 A100378 A100379

KEYWORD

nonn

AUTHOR

Labos E. (labos(AT)ana.sote.hu), Dec 09 2004

EXTENSIONS

Edited by Don Reble (djr(AT)nk.ca), Jun 13 2007

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Last modified February 14 17:38 EST 2012. Contains 205647 sequences.