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A086287
Greatest prime factor of 7-smooth numbers.
2
1, 2, 3, 2, 5, 3, 7, 2, 3, 5, 3, 7, 5, 2, 3, 5, 7, 3, 5, 3, 7, 5, 2, 7, 3, 5, 7, 5, 3, 7, 5, 3, 7, 5, 7, 2, 7, 3, 5, 5, 3, 7, 5, 3, 7, 5, 7, 3, 7, 5, 5, 7, 2, 5, 7, 3, 7, 5, 5, 3, 7, 7, 5, 7, 3, 7, 5, 7, 3, 7, 5, 5, 3, 7, 5, 7, 2, 5, 7, 3, 7, 5, 7, 5, 3, 7, 7, 7, 5, 5, 7, 3, 7, 5, 5, 7, 3, 7, 7, 5
OFFSET
1,2
LINKS
FORMULA
a(n) = A006530(A002473(n)).
A086286(n) <= a(n) <= 7.
MATHEMATICA
Reap[Do[p = FactorInteger[n][[-1, 1]]; If[p < 11, Sow[p]], {n, 1, 500}] ][[2, 1]] (* Jean-François Alcover, Dec 17 2017 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Jul 15 2003
STATUS
approved