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A057143 Largest of the most frequently occurring numbers in 1-to-n multiplication table. 7
1, 2, 6, 4, 4, 12, 12, 24, 24, 40, 40, 24, 24, 24, 60, 60, 60, 36, 36, 60, 60, 60, 60, 120, 120, 120, 120, 168, 168, 120, 120, 120, 120, 120, 120, 180, 180, 180, 180, 120, 120, 120, 120, 120, 360, 360, 360, 360, 360, 360, 360, 360, 360, 360, 360, 360, 360, 360 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
Branden Aldridge, Table of n, a(n) for n = 1..20000 (first 1000 terms from Reinhard Zumkeller).
EXAMPLE
M(n) is the array in which m(x,y)= x*y for x = 1 to n and y = 1 to n. In M(10), the most frequently occurring numbers are 6, 8, 10, 12, 18, 20, 24, 30,40, each occurring 4 times. The largest of these numbers is 40, so a(10) = 40.
PROG
(Haskell)
import Data.List (group, sort, sortBy)
import Data.Function (on)
a057143 n = head $ head $ reverse $ sortBy (compare `on` length) $
group $ sort [u * v | u <- [1..n], v <- [1..n]]
-- Reinhard Zumkeller, Jun 22 2013
CROSSREFS
Sequence in context: A249913 A003077 A323482 * A087428 A115508 A348669
KEYWORD
nonn
AUTHOR
Arran Fernandez, Aug 13 2000
EXTENSIONS
More terms from Larry Reeves (larryr(AT)acm.org), Apr 18 2001
STATUS
approved

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Last modified June 13 10:24 EDT 2024. Contains 373383 sequences. (Running on oeis4.)