cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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

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Author

Paul D. Hanna, Jan 10 2008

Keywords

Comments

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.
The Bell transform of (-1)^n*A048287(n+1). For the definition of the Bell transform see A264428. - Peter Luschny, Jan 18 2016

Examples

			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; ...
		

Crossrefs

Cf. columns: A048287, A136596, A136597; A136590 (matrix inverse); A136588, A136589.

Programs

  • Maple
    # The function BellMatrix is defined in A264428.
    BellMatrix(n -> (-1)^n*A048287(n+1), 9); # Peter Luschny, Jan 27 2016
  • Mathematica
    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 *)
  • PARI
    {T(n,k) = if(n
    				
  • 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
    				
  • Sage
    # uses[bell_matrix from A264428]
    bell_matrix(lambda n: (-1)^n*A048287(n+1), 10) # Peter Luschny, Jan 18 2016

Formula

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).