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A213736
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Triangle read by rows, coefficients of the Swiss-Knife median polynomials M_{n}(x) in descending order of powers.
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0
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1, 1, -1, -1, 1, -2, -5, 6, 4, 1, -3, -12, 29, 57, -72, -46, 1, -4, -22, 80, 261, -660, -1264, 1608, 1024, 1, -5, -35, 170, 775, -2941, -9385, 23880, 45620, -58080, -36976, 1, -6, -51, 310, 1815, -9186, -41033, 156618, 498660, -1269720, -2425056, 3087648
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OFFSET
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0,6
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COMMENTS
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LINKS
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EXAMPLE
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M(0,x) = 1,
M(1,x) = x^2-x-1,
M(2,x) = x^4-2*x^3-5*x^2+6*x+4,
M(3,x) = x^6-3*x^5-12*x^4+29*x^3+57*x^2-72*x-46.
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MAPLE
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A213736_triangle := proc(n) local A, len, k, m, sk_poly;
len := 2*n-1; A := array(0..len, 0..len);
sk_poly := proc(n, x) local v, k;
add(`if`((k+1)mod 4 = 0, 0, (-1)^iquo(k+1, 4))*2^iquo(-k, 2)*
add((-1)^v*binomial(k, v)*(v+x+1)^n, v=0..k), k=0..n) end:
for m from 0 to len do A[m, 0] := sk_poly(m, x);
for k from m-1 by -1 to 0 do
A[k, m-k] := A[k+1, m-k-1] - A[k, m-k-1] od od;
seq(print(seq(coeff(A[k, k], x, 2*k-i), i=0..2*k)), k=0..n-1) end:
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CROSSREFS
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KEYWORD
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sign,tabf
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AUTHOR
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STATUS
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approved
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