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A100387
a(n) is the largest number x such that for m=n to n+x-1, A006530(m) decreases.
1
1, 2, 1, 2, 1, 2, 1, 1, 1, 2, 1, 4, 3, 2, 1, 2, 1, 2, 1, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 2, 1, 1, 3, 2, 1, 4, 3, 2, 1, 2, 1, 3, 2, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 1, 1, 2, 1, 4, 3, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 3, 2, 1, 2, 1, 1, 3, 2, 1, 1, 2, 1, 1, 3, 2, 1, 2, 1, 1, 1, 1, 3, 2, 1, 2, 1, 2, 1, 2, 1, 3, 2, 1
OFFSET
2,2
COMMENTS
A006530(m) is the largest prime factor of m.
FORMULA
From Pontus von Brömssen, Nov 09 2022: (Start)
a(n) = 1 if and only if n >= 2 and n is a term of A070089.
If a(n) > 1 then a(n) = a(n+1)+1.
(End)
EXAMPLE
a(13)=4 because the largest prime factors of 13,14,15,16 are 13,7,5,2; but A006530(17)=17.
MATHEMATICA
<<NumberTheory`NumberTheoryFunctions` mxp[x_] :=Max[PrimeFactorList[x]]; uph=Table[First[Flatten[Position[Sign[RotateLeft[Table[mxp[n+j], {j, 0, 15}]]-Table[mxp[n+j], {j, 0, 15}]], 1]]], {n, 1, 256}]
KEYWORD
nonn
AUTHOR
Labos Elemer, Dec 10 2004
EXTENSIONS
Edited by Don Reble, Jun 13 2007
STATUS
approved