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 A119828 Number triangle T(n,k)=(2n)!/(2k)!. 3
 1, 2, 1, 24, 12, 1, 720, 360, 30, 1, 40320, 20160, 1680, 56, 1, 3628800, 1814400, 151200, 5040, 90, 1, 479001600, 239500800, 19958400, 665280, 11880, 132, 1, 87178291200, 43589145600, 3632428800, 121080960, 2162160, 24024, 182, 1 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Row sums are A051396(n+1). Diagonal sums are A119829. Inverse is the bi-diagonal array A119830. E.g.f. cosh(x*y)/(1-y*x^2) produces an aerated version. LINKS FORMULA Number triangle T(n,k)=[k<=n](2n)!/(2k)! EXAMPLE Triangle begins 1, 2, 1, 24, 12, 1, 720, 360, 30, 1, 40320, 20160, 1680, 56, 1, 3628800, 1814400, 151200, 5040, 90, 1 CROSSREFS Sequence in context: A073876 A355587 A276399 * A328826 A297892 A101179 Adjacent sequences: A119825 A119826 A119827 * A119829 A119830 A119831 KEYWORD easy,nonn,tabl AUTHOR Paul Barry, May 25 2006 STATUS approved

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Last modified February 4 10:20 EST 2023. Contains 360053 sequences. (Running on oeis4.)