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.

A106436 Difference array of Bell numbers A000110 read by antidiagonals.

Original entry on oeis.org

1, 0, 1, 1, 1, 2, 1, 2, 3, 5, 4, 5, 7, 10, 15, 11, 15, 20, 27, 37, 52, 41, 52, 67, 87, 114, 151, 203, 162, 203, 255, 322, 409, 523, 674, 877, 715, 877, 1080, 1335, 1657, 2066, 2589, 3263, 4140, 3425, 4140, 5017, 6097, 7432, 9089, 11155, 13744, 17007, 21147
Offset: 0

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Author

Philippe Deléham, May 29 2005

Keywords

Comments

Essentially Aitken's array A011971 with first column A000296.
Mirror image of A182930. - Alois P. Heinz, Jan 29 2019

Examples

			   1;
   0,  1;
   1,  1,  2;
   1,  2,  3,  5;
   4,  5,  7, 10, 15;
  11, 15, 20, 27, 37, 52;
  ...
		

Crossrefs

T(2n,n) gives A020556.

Programs

  • Maple
    b:= proc(n) option remember; `if`(n=0, 1, add(
          b(n-j)*binomial(n-1, j-1), j=1..n))
        end:
    T:= proc(n, k) option remember; `if`(k=0, b(n),
          T(n+1, k-1)-T(n, k-1))
        end:
    seq(seq(T(n, d-n), n=0..d), d=0..12);  # Alois P. Heinz, Jan 29 2019
  • Mathematica
    bb = Array[BellB, m = 12, 0];
    dd[n_] := Differences[bb, n];
    A = Array[dd, m, 0];
    Table[A[[n-k+1, k+1]], {n, 0, m-1}, {k, 0, n}] // Flatten (* Jean-François Alcover, May 26 2019 *)
    a[0,0]:=1; a[n_,0]:=a[n-1,n-1]-a[n-1,0]; a[n_,k_]/;0Oliver Seipel, Nov 23 2024 *)

Formula

Double-exponential generating function: sum_{n, k} a(n-k, k) x^n/n! y^k/k! = exp(exp{x+y}-1-x). a(n,k) = Sum_{i=k..n} (-1)^(n-i)*binomial(n-k,i-k)*Bell(i). - Vladeta Jovovic, Oct 14 2006