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A124032
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Triangle read by rows: T(n,k) is the coefficient of x^k in the polynomial p(n,x) defined by p(0,x)=1, p(1,x)=-1-x, p(n,x)=((-1)^(n-1)-x)*p(n-1,x)-p(n-2,x) for n>=2 (0<=k<=n).
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1
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1, -1, -1, 0, 2, 1, 1, 3, -1, -1, -1, -6, -3, 2, 1, -2, -8, 4, 6, -1, -1, 3, 16, 7, -12, -6, 2, 1, 5, 21, -13, -25, 7, 9, -1, -1, -8, -42, -15, 50, 24, -18, -9, 2, 1, -13, -55, 40, 90, -33, -51, 10, 12, -1, -1, 21, 110, 30, -180, -81, 102, 50, -24, -12, 2, 1
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OFFSET
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0,5
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LINKS
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EXAMPLE
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Triangle begins:
{1},
{-1, -1},
{0, 2, 1},
{1,3, -1, -1},
{-1, -6, -3, 2, 1},
{-2, -8, 4, 6, -1, -1},
{3, 16, 7, -12, -6, 2, 1},
{5, 21, -13, -25, 7, 9, -1, -1},
{-8, -42, -15, 50, 24, -18, -9, 2, 1},
{-13, -55, 40, 90, -33, -51, 10, 12, -1, -1},
{21,110, 30, -180, -81, 102, 50, -24, -12, 2, 1}}
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MAPLE
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p[0]:=1: p[1]:=-1-x: for n from 2 to 12 do p[n]:=sort(expand(((-1)^(n-1)-x)*p[n-1]-p[n-2])) od: T:=(n, k)->coeff(p[n], x, k): for n from 0 to 12 do seq(T(n, k), k=0..n) od; # yields sequence in triangular form
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MATHEMATICA
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b[k_] = (-1)^k; a[k_] = -1; p[0, x] = 1; p[1, x] = (x - b[1])/a[1]; p[k_, x_] :=p[k, x] = ((x - b[k - 1])*p[k - 1, x] - a[k - 2] *p[k - 2, x])/a[k - 1]; w = Table[CoefficientList[p[n, x], x], {n, 0, 10}]; Flatten[w]
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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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