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.

A088729 Matrix product of Stirling2-triangle A008277(n,k) and unsigned Lah-triangle |A008297(n,k)|.

Original entry on oeis.org

1, 3, 1, 13, 9, 1, 75, 79, 18, 1, 541, 765, 265, 30, 1, 4683, 8311, 3870, 665, 45, 1, 47293, 100989, 59101, 13650, 1400, 63, 1, 545835, 1362439, 960498, 278901, 38430, 2618, 84, 1, 7087261, 20246445, 16700545, 5844510, 1012431, 92610, 4494, 108, 1
Offset: 1

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Author

Vladeta Jovovic, Nov 22 2003

Keywords

Comments

Also the Bell transform of A000670(n+1). For the definition of the Bell transform see A264428. - Peter Luschny, Jan 26 2016
Also the number of k-dimensional flats of the n-dimensional Catalan arrangement. - Shuhei Tsujie, May 05 2019

Crossrefs

Cf. A000670(first column), A075729(row sums).

Programs

  • Maple
    # The function BellMatrix is defined in A264428.
    # Adds (1, 0, 0, 0, ..) as column 0.
    BellMatrix(n -> add(combinat:-eulerian1(n+1, k)*2^k, k=0..n+1), 9); # Peter Luschny, Jan 26 2016
  • Mathematica
    BellMatrix[f_, len_] := With[{t = Array[f, len, 0]}, Table[BellY[n, k, t], {n, 0, len - 1}, {k, 0, len - 1}]];
    rows = 12;
    B = BellMatrix[Function[n, HurwitzLerchPhi[1/2, -n-1, 0]/2], rows];
    Table[B[[n, k]], {n, 2, rows}, {k, 2, n}] // Flatten (* Jean-François Alcover, Jun 27 2018, after Peter Luschny *)

Formula

E.g.f.: exp((exp(x)-1)*y/(2-exp(x))).