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A124845
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Triangle read by rows: T(n,k) = (3 - (-1)^k)*binomial(n,k)/2 (0 <= k <= n).
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1
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1, 1, 2, 1, 4, 1, 1, 6, 3, 2, 1, 8, 6, 8, 1, 1, 10, 10, 20, 5, 2, 1, 12, 15, 40, 15, 12, 1, 1, 14, 21, 70, 35, 42, 7, 2, 1, 16, 28, 112, 70, 112, 28, 16, 1, 1, 18, 36, 168, 126, 252, 84, 72, 9, 2, 1, 20, 45, 240, 210, 504, 210, 240, 45, 20, 1, 1, 22, 55, 330, 330, 924, 462, 660, 165
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OFFSET
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0,3
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LINKS
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EXAMPLE
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First few rows of the triangle:
1;
1, 2;
1, 4, 1;
1, 6, 3, 2;
1, 8, 6, 8, 1;
1, 10, 10, 20, 5, 2;
1, 12, 15, 40, 15, 12, 1;
...
Row 3 sum = 12 = (1 + 6 + 3 + 2) = A003945(3).
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MAPLE
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T:=(n, k)->(3-(-1)^k)*binomial(n, k)/2: for n from 0 to 12 do seq(T(n, k), k=0..n) od; # yields sequence in triangular form
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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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