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A152204
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Triangle read by rows: T(n,k) = 2*n-4*k+5 (n >= 0, 1 <= k <= 1+floor(n/2)).
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6
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1, 3, 5, 1, 7, 3, 9, 5, 1, 11, 7, 3, 13, 9, 5, 1, 15, 11, 7, 3, 17, 13, 9, 5, 1, 19, 15, 11, 7, 3, 21, 17, 13, 9, 5, 1, 23, 19, 15, 11, 7, 3, 25, 21, 17, 13, 9, 5, 1, 27, 23, 19, 15, 11, 7, 3, 29, 25, 21, 17, 13, 9, 5, 1, 31, 27, 23, 19, 15, 11, 7, 3, 33
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OFFSET
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0,2
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COMMENTS
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All terms are odd, decreasing across rows. Row sums = A000217, the triangular numbers.
Triangle read by rows formed from the antidiagonals of triangle A099375.
The alternating row sums equal A098181(n). (End)
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LINKS
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FORMULA
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By columns, odd terms in every column, n-th column starts at row (2*n).
T(n, k) = A099375(n-k+1, k-1), n >= 0 and 1 <= k <= 1+floor(n/2)).
T(n, k) = A158405(n+1, n-2*k+2). (End)
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EXAMPLE
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First few rows of the triangle =
1
3
5 1
7 3
9 5 1
11 7 3
13 9 5 1
15 11 7 3
17 13 9 5 1
19 15 11 7 3
21 17 13 9 5 1
...
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MAPLE
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T := proc(n, k) return 2*n-4*k+5: end: seq(seq(T(n, k), k=1..1+floor(n/2)), n=0..20); # Nathaniel Johnston, May 01 2011
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CROSSREFS
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KEYWORD
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nonn,tabf,easy
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AUTHOR
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EXTENSIONS
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Edited by N. J. A. Sloane, Sep 25 2010, following a suggestion from Emeric Deutsch
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STATUS
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approved
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