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A143971
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Triangle read by rows, (3n-2) subsequences decrescendo
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2
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1, 4, 1, 7, 4, 1, 10, 7, 4, 1, 13, 10, 7, 4, 1, 16, 13, 10, 7, 4, 1, 19, 16, 13, 10, 7, 4, 1, 22, 19, 16, 13, 10, 7, 4, 1, 25, 22, 19, 16, 13, 10, 7, 4, 1, 28, 25, 22, 19, 16, 13, 10, 7, 4, 1, 31, 28, 25, 22, 19, 16, 13, 10, 7, 4, 1
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OFFSET
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1,2
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COMMENTS
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Row sums = pentagonal numbers, A000326: (1, 5, 12, 22, 35,...).
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LINKS
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FORMULA
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Triangle read by rows, (3n-2) subsequences decrescendo; 1<=k<=n.
(1, 4, 7, 10, 13,...) in every column.
T(n,k) = 3*n - 3*k + 1.
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EXAMPLE
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Triangle starts
1;
4, 1;
7, 4, 1;
10, 7, 4, 1;
...
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MAPLE
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T := (n, k) -> 3*n-3*k+1: seq(seq(T(n, k), k=1..n), n=1..11); # Johannes W. Meijer, Sep 05 2013
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CROSSREFS
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KEYWORD
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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