A136595
Matrix inverse of triangle A136590.
Original entry on oeis.org
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
Offset: 0
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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# The function BellMatrix is defined in A264428.
BellMatrix(n -> (-1)^n*A048287(n+1), 9); # Peter Luschny, Jan 27 2016
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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];
Table[M[[n, k]], {n, 1, rows}, {k, 1, n}] // Flatten (* Jean-François Alcover, Jun 24 2018, after Peter Luschny *)
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{T(n,k) = if(n
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/* 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
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# uses[bell_matrix from A264428]
bell_matrix(lambda n: (-1)^n*A048287(n+1), 10) # Peter Luschny, Jan 18 2016
Original entry on oeis.org
1, 1, -4, 6, 24, -240, 720, 5040, -80640, 362880, 3628800, -79833600, 479001600, 6227020800, -174356582400, 1307674368000, 20922789888000, -711374856192000, 6402373705728000, 121645100408832000, -4865804016353280000, 51090942171709440000
Offset: 1
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{a(n) = n!*polcoeff( log(1+x+x^2 +x*O(x^(n+1))),n)}
for(n=1,30,print1(a(n),", "))
Original entry on oeis.org
1, 3, -13, -10, 394, -2016, -5076, 170064, -1155024, -5005440, 193724640, -1656720000, -10280355840, 465087087360, -4804977542400, -39012996556800, 2035558551398400, -24660231399014400, -248246498826547200, 14713557956794368000
Offset: 2
E.g.f.: A(x) = 1*x^2/2! + 3*x^3/3! - 13*x^4/4! - 10*x^5/5! + 394*x^6/6! +...
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With[{nn=30},Drop[CoefficientList[Series[Log[1+x+x^2]^2/2,{x,0,nn}],x] Range[ 0,nn]!,2]] (* Harvey P. Dale, Feb 28 2013 *)
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a(n)=(n+2)!*polcoeff(log(1+x+x^2 +x*O(x^(n+2)))^2/2!,n+2)
Original entry on oeis.org
1, 6, -25, -135, 1834, -3668, -110692, 1339020, -1181664, -164709864, 2206092096, 395662176, -463716547776, 7029335571840, 8900411569920, -2265668505227520, 38689597829053440, 92447263589921280, -17785648201625856000, 338957966532455424000
Offset: 3
E.g.f.: A(x) = 1*x^3/3! + 6*x^4/4! - 25*x^5/5! - 135*x^6/6! + 1834*x^7/7! -...
A136594
Unsigned row sums of triangle A136590.
Original entry on oeis.org
1, 1, 2, 8, 26, 70, 820, 5152, 20316, 388712, 3666188, 17298908, 501805832, 6256792412, 33844737292, 1353617016078, 20960708128068, 137741948419428, 6588092586831028, 121860622573650906, 924837580461274556
Offset: 0
A048287
Number of semiorders on n labeled nodes whose incomparability graph is connected.
Original entry on oeis.org
1, 1, 7, 61, 751, 11821, 226927, 5142061, 134341711, 3975839341, 131463171247, 4803293266861, 192178106208271, 8356430510670061, 392386967808249967, 19788154572706556461, 1066668756919315412431, 61204224384073232815981
Offset: 1
a(3)=7, the seven semiorders being three disjoint points and the disjoint union of a point and a two-element chain (with six labelings).
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A048287 := n -> add((-1)^(n-k-1)*Stirling2(n,k+1)*(2*k)!/k!, k=0..n-1):
seq(A048287(n), n=1..18); # Peter Luschny, Jan 27 2016
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Table[Sum[(-1)^(n - k) StirlingS2[n, k] k!*CatalanNumber[k - 1], {k, n}], {n, 20}] (* Michael De Vlieger, Jan 27 2016 *)
Rest[Range[0, 18]! CoefficientList[Series[1 - 2 (1 - Exp[-x]) /(1 - Sqrt[4 Exp[-x] - 3]), {x, 0, 18}], x]] (* Vincenzo Librandi, Jan 28 2016 *)
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{a(n)=local(A136590=matrix(n+1,n+1,r,c,if(r>=c,(r-1)!/(c-1)!*polcoeff(log(1+x+x^2 +x*O(x^n))^(c-1),r-1))));(-1)^(n+1)*(A136590^-1)[n+1,2]} \\ Paul D. Hanna, Jan 10 2008
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{a(n) = if( n<0, 0, n! * polcoeff( (1 - sqrt(4*exp(-x + x*O(x^n)) - 3)) / 2, n))}; /* Michael Somos, Nov 26 2017 */
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{a(n) = if( n<1, 0, n! * polcoeff( serreverse( -log(1 - x + x^2 + x * O(x^n))), n))}; /* Michael Somos, Nov 26 2017 */
Showing 1-6 of 6 results.
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