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A129684
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Exponential Riordan array [1/(1-x^2/2), x].
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2
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1, 0, 1, 1, 0, 1, 0, 3, 0, 1, 6, 0, 6, 0, 1, 0, 30, 0, 10, 0, 1, 90, 0, 90, 0, 15, 0, 1, 0, 630, 0, 210, 0, 21, 0, 1, 2520, 0, 2520, 0, 420, 0, 28, 0, 1, 0, 22680, 0, 7560, 0, 756, 0, 36, 0, 1, 113400, 0, 113400, 0, 18900, 0, 1260, 0, 45, 0, 1
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OFFSET
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0,8
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COMMENTS
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LINKS
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FORMULA
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Number triangle T(n,k) = [k<=n](n!/k!)*(1/2^((n-k)/2))*(1+(-1)^(n-k))/2.
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EXAMPLE
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Triangle begins
1,
0, 1,
1, 0, 1,
0, 3, 0, 1,
6, 0, 6, 0, 1,
0, 30, 0, 10, 0, 1,
90, 0, 90, 0, 15, 0, 1,
0, 630, 0, 210, 0, 21, 0, 1
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MATHEMATICA
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(* The function RiordanArray is defined in A256893. *)
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CROSSREFS
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KEYWORD
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AUTHOR
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STATUS
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approved
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