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A125694
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Riordan array ((1+3x-sqrt(1+2x+9x^2))/(2x),(1+3x-sqrt(1+2x+9x^2))/2).
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3
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1, -2, 1, 2, -4, 1, 2, 8, -6, 1, -10, -4, 18, -8, 1, 6, -24, -26, 32, -10, 1, 42, 60, -18, -72, 50, -12, 1, -102, 24, 162, 48, -150, 72, -14, 1, -82, -388, -214, 248, 230, -268, 98, -16, 1, 782, 536, -546, -800, 158, 600
(list; table; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| First column is A125695. Row sums are A091593. Inverse of A125693.
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FORMULA
| T(n-1,k-1) = (k/n)*sum_{i=0..n-k} binomial(n,n-k-i) *(-3)^(n-k-i) *binomial(i+n-1,n-1). [From Vladimir Kruchinin, Feb 12 2011]
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EXAMPLE
| Triangle begins
1,
-2, 1,
2, -4, 1,
2, 8, -6, 1,
-10, -4, 18, -8, 1,
6, -24, -26, 32, -10, 1,
42, 60, -18, -72, 50, -12, 1
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CROSSREFS
| Sequence in context: A129994 A080246 A113413 * A136678 A110162 A199087
Adjacent sequences: A125691 A125692 A125693 * A125695 A125696 A125697
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KEYWORD
| easy,sign,tabl
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AUTHOR
| Paul Barry (pbarry(AT)wit.ie), Nov 30 2006
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