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 A124744 Expansion of (1+x*y)/(1-x^2*y^2+x^3*y^2). 4
 1, 0, 1, 0, 0, 1, 0, 0, -1, 1, 0, 0, 0, -1, 1, 0, 0, 0, 0, -2, 1, 0, 0, 0, 0, 1, -2, 1, 0, 0, 0, 0, 0, 1, -3, 1, 0, 0, 0, 0, 0, 0, 3, -3, 1, 0, 0, 0, 0, 0, 0, -1, 3, -4, 1, 0, 0, 0, 0, 0, 0, 0, -1, 6, -4, 1 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,20 COMMENTS Row sums are A124745. Diagonal sums are A124746. Inverse is A124747. LINKS Table of n, a(n) for n=0..65. FORMULA Number triangle T(n,k)=C(floor(k/2),n-k)*(-1)^(n-k) Column k has g.f. x^k*(1-x)^floor(k/2). - Paul Barry, Feb 01 2007 EXAMPLE Triangle begins 1, 0, 1, 0, 0, 1, 0, 0, -1, 1, 0, 0, 0, -1, 1, 0, 0, 0, 0, -2, 1, 0, 0, 0, 0, 1, -2, 1, 0, 0, 0, 0, 0, 1, -3, 1, 0, 0, 0, 0, 0, 0, 3, -3, 1, 0, 0, 0, 0, 0, 0, -1, 3, -4, 1, 0, 0, 0, 0, 0, 0, 0, -1, 6, -4, 1 CROSSREFS Sequence in context: A321854 A227839 A291748 * A124788 A284504 A281245 Adjacent sequences: A124741 A124742 A124743 * A124745 A124746 A124747 KEYWORD easy,sign,tabl AUTHOR Paul Barry, Nov 06 2006 STATUS approved

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Last modified December 10 00:12 EST 2023. Contains 367696 sequences. (Running on oeis4.)