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.

A134836 Antidiagonals of the array: A007318 * A002260(transposed).

Original entry on oeis.org

1, 1, 1, 1, 3, 1, 1, 5, 3, 1, 1, 7, 8, 3, 1, 1, 9, 16, 8, 3, 1, 1, 11, 27, 20, 8, 3, 1, 1, 13, 41, 43, 20, 8, 3, 1, 1, 15, 58, 81, 48, 20, 8, 3, 1, 1, 17, 78, 138, 106, 48, 20, 8, 3, 1, 1, 19, 101, 218, 213, 112, 48, 20, 8, 3, 1
Offset: 1

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Author

Gary W. Adamson, Nov 12 2007

Keywords

Comments

Antidiagonals tend to A001792 starting from the right: (1, 3, 8, 20, 48, 112, ...).

Examples

			First few rows of the array:
  1,  1,  1,  1,   1,   1, ...;
  1,  3,  3,  3,   3,   3, ...;
  1,  5,  8,  8,   8,   8, ...;
  1,  7, 16, 20,  20,  20, ...;
  1,  9, 27, 43,  48,  48, ...;
  1, 11, 41, 81, 106, 112, ...;
  ...
First few rows of the triangle:
  1;
  1,  1;
  1,  3,  1;
  1,  5,  3,  1;
  1,  7,  8,  3,  1;
  1,  9, 16,  8,  3,  1;
  1, 11, 27, 20,  8,  3,  1;
  1, 13, 41, 43, 20,  8,  3,  1;
  ...
		

Crossrefs

Cf. A002260, A001792, A116445 (array transposed), A001629 (antidiagonal sums).

Programs

  • Maple
    A002260 := proc(n,k)
        if n <= k then
            n+1;
        else
            0 ;
        end if;
    end proc:
    A007318 := proc(n,k)
        if k <= n then
            binomial(n,k) ;
        else
            0
        end if;
    end proc:
    A134836 := proc(n,k)
        add( A007318(n,i)*A002260(i,k),i=0..k) ;
    end proc:
    seq(seq(A134836(d-k,k),k=0..d),d=0..12) ; # R. J. Mathar, Aug 17 2022

Formula

Antidiagonals of the array: A007318 * A002260(transform), where A002260 = (1; 1,2; 1,2,3; ...).

Extensions

One term corrected by R. J. Mathar, Aug 17 2022