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A070861
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Triangle of all possible distinct numbers obtained as a product of distinct numbers from 1..n.
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4
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1, 1, 2, 1, 2, 3, 6, 1, 2, 3, 4, 6, 8, 12, 24, 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 24, 30, 40, 60, 120, 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 18, 20, 24, 30, 36, 40, 48, 60, 72, 90, 120, 144, 180, 240, 360, 720, 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 15, 18, 20, 21, 24, 28, 30, 35, 36, 40, 42
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,3
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COMMENTS
| Factorials are a subsequence (A000142). [Reinhard Zumkeller, Jul 02 2011]
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LINKS
| Reinhard Zumkeller, Rows n=1..20 of triangle, flattened
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EXAMPLE
| Triangle begins
1;
1,2;
1,2,3,6;
1,2,3,4,6,8,12,24; ...
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PROG
| (Haskell)
a070861 n = a070861_list !! (n-1)
a070861_list = concat a070861_tabf
a070861_tabf = [1] : f 2 [1] where
f n ps = ps' : f (n+1) ps' where ps' = m ps $ map (n*) ps
m [] ys = ys
m xs'@(x:xs) ys'@(y:ys)
| x < y = x : m xs ys'
| x == y = x : m xs ys
| otherwise = y : m xs' ys
b070861 = bFile' "A070861" (concat $ take 20 a070861_tabf) 1
-- Reinhard Zumkeller, Jul 02 2011
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CROSSREFS
| Cf. A060957, A070863.
Sequence in context: A078777 A135938 A079210 * A106524 A086582 A033639
Adjacent sequences: A070858 A070859 A070860 * A070862 A070863 A070864
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KEYWORD
| nonn,tabf
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AUTHOR
| Amarnath Murthy (amarnath_murthy(AT)yahoo.com), May 16 2002
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EXTENSIONS
| Corrected and extended by Lior Manor (lior.manor(AT)gmail.com) May 23 2002
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