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A225800
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Triangle of rising diagonals of A011973 (with rows displayed as centered text).
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0
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 2, 1, 1, 5, 4, 1, 1, 7, 6, 1, 1, 1, 9, 8, 6, 3, 1, 1, 11, 10, 15, 10, 1, 1, 13, 12, 28, 21, 1, 1, 1, 15, 14, 45, 36, 10, 4, 1, 1, 17, 16, 66, 55, 35, 20, 1, 1, 19, 18, 91, 78, 84, 56, 1, 1, 1, 21, 20, 120, 105, 165, 120, 15, 5, 1
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listen;
history;
text;
internal format)
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OFFSET
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1,11
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COMMENTS
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LINKS
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FORMULA
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r(n) = binomial[2n-k-2-3floor(k/2),floor(k/2)); {k, 0,...,floor((2n-1)/3)}. - John Molokach, Jul 29 2013
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EXAMPLE
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Triangle begins:
1;
1, 1;
1, 1;
1, 1, 1;
1, 1, 3, 2;
1, 1, 5, 4;
1, 1, 7, 6, 1;
1, 1, 9, 8, 6, 3;
1, 1, 11, 10, 15, 10;
1, 1, 13, 12, 28, 21, 1;
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MATHEMATICA
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Table[Binomial[2 n - k - 2 - 3 Floor[k/2], Floor[k/2]], {n, 1, 25}, {k, 0, Floor[(2 n - 1)/3]}] (* John Molokach, Jul 29 2013 *)
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CROSSREFS
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KEYWORD
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nonn,tabf
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AUTHOR
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STATUS
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approved
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