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A136595
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Matrix inverse of triangle A136590.
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6
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1, 0, 1, 0, -1, 1, 0, 7, -3, 1, 0, -61, 31, -6, 1, 0, 751, -375, 85, -10, 1, 0, -11821, 5911, -1350, 185, -15, 1, 0, 226927, -113463, 26341, -3710, 350, -21, 1, 0, -5142061, 2571031, -603246, 87381, -8610, 602, -28, 1, 0, 134341711, -67170855, 15887845, -2346330, 240051, -17766
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OFFSET
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0,8
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COMMENTS
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A136590 is the triangle of trinomial logarithmic coefficients.
Column 1 is signed A048287, which is the number of semiorders on n labeled nodes whose incomparability graph is connected.
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LINKS
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FORMULA
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T(n,k) = Sum_{i=0..n-1} (-1)^i * (k+i)! * Stirling2(n,k+i) * Catalan(k,i)/k!, where Stirling2(n,k) = A008277(n,k); Catalan(k,i) = C(2i+k,i)*k/(2i+k) = coefficient of x^i in C(x)^k with C(x) = (1-sqrt(1-4x))/(2x).
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EXAMPLE
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Triangle begins:
1;
0, 1;
0, -1, 1;
0, 7, -3, 1;
0, -61, 31, -6, 1;
0, 751, -375, 85, -10, 1;
0, -11821, 5911, -1350, 185, -15, 1;
0, 226927, -113463, 26341, -3710, 350, -21, 1;
0, -5142061, 2571031, -603246, 87381, -8610, 602, -28, 1;
0, 134341711, -67170855, 15887845, -2346330, 240051, -17766, 966, -36, 1; ...
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MAPLE
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# The function BellMatrix is defined in A264428.
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MATHEMATICA
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BellMatrix[f_Function, len_] := With[{t = Array[f, len, 0]}, Table[BellY[n, k, t], {n, 0, len - 1}, {k, 0, len - 1}]];
rows = 11;
M = BellMatrix[Sum[(-1)^(k+1) k! StirlingS2[#+1, k] CatalanNumber[k-1], {k, 1, #+1}]&, rows];
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PROG
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(PARI) {T(n, k) = if(n<k||k<0, 0, if(n==k, 1, if(k==0, 0, n!/(k-1)!* sum(i=0, n-1, (-1)^i * polcoeff(((exp(x + x*O(x^n)) - 1)^(k+i)), n) * binomial(2*i+k, i)/(2*i+k)))))}
for(n=0, 10, for(k=0, n, print1(T(n, k), ", ")); print(""))
(PARI) /* Define Stirling2: */
{Stirling2(n, k) = n!*polcoeff(((exp(x+x*O(x^n))-1)^k)/k!, n)}
/* Define Catalan(m, n) = [x^n] C(x)^m: */
{CATALAN(m, n) = binomial(2*n+m, n) * m/(2*n+m)}
/* Define this triangle: */
{T(n, k) = if(n<k||k<0, 0, if(n==k, 1, if(k==0, 0, sum(i=0, n-1, (-1)^i*(k+i)!*Stirling2(n, k+i) * CATALAN(k, i)/k!))))}
for(n=0, 10, for(k=0, n, print1(T(n, k), ", ")); print(""))
(Sage) # uses[bell_matrix from A264428]
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CROSSREFS
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KEYWORD
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AUTHOR
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STATUS
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approved
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