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A120423 a(n) = maximum value among all k where 1<=k<=n of GCD(k,floor(n/k)). 0
1, 1, 1, 2, 2, 1, 1, 2, 3, 3, 3, 2, 2, 2, 2, 4, 4, 4, 4, 3, 3, 3, 3, 2, 5, 5, 5, 5, 5, 3, 3, 4, 4, 4, 4, 6, 6, 6, 6, 6, 6, 3, 3, 3, 3, 3, 3, 4, 7, 7, 7, 7, 7, 7, 7, 5, 5, 5, 5, 3, 3, 3, 3, 8, 8, 8, 8, 8, 8, 8, 8, 6, 6, 6, 6, 6, 6, 6, 6, 6, 9, 9, 9, 9, 9, 9, 9, 9, 9, 4, 4, 4, 4, 4, 4, 4, 4, 7, 7, 10, 10, 10, 10 (list; graph; refs; listen; history; internal format)
OFFSET

1,4

EXAMPLE

For n = 10, we have the pairs {k,floor(n/k)} of {1,10},{2,5},{3,3},{4,2},{5,2},{6,1},{7,1},{8,1},{9,1},{10,1}. The GCD's of these 10 pairs are 1,1,3,2,1,1,1,1,1,1. Of these, 3 is the largest. So a(10) = 3.

MAPLE

a:=n->max(seq(gcd(k, floor(n/k)), k=1..n)): seq(a(n), n=1..112); - Emeric Deutsch (deutsch(AT)duke.poly.edu), Jul 24 2006

MATHEMATICA

Table[Max[Table[GCD[k, Floor[n/k]], {k, 1, n}]], {n, 1, 100}] - Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Jul 22 2006

CROSSREFS

Sequence in context: A004739 A156282 A203776 * A113137 A199204 A075402

Adjacent sequences:  A120420 A120421 A120422 * A120424 A120425 A120426

KEYWORD

nonn

AUTHOR

Leroy Quet Jul 11 2006

EXTENSIONS

More terms from Stefan Steinerberger (stefan.steinerberger(AT)gmail.com) and Emeric Deutsch (deutsch(AT)duke.poly.edu), Jul 22 2006

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Last modified February 14 22:01 EST 2012. Contains 205667 sequences.