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.

Showing 1-2 of 2 results.

A059365 Another version of the Catalan triangle: T(r,s) = binomial(2*r-s-1,r-1) - binomial(2*r-s-1,r), r>=0, 0 <= s <= r.

Original entry on oeis.org

0, 0, 1, 0, 1, 1, 0, 2, 2, 1, 0, 5, 5, 3, 1, 0, 14, 14, 9, 4, 1, 0, 42, 42, 28, 14, 5, 1, 0, 132, 132, 90, 48, 20, 6, 1, 0, 429, 429, 297, 165, 75, 27, 7, 1, 0, 1430, 1430, 1001, 572, 275, 110, 35, 8, 1, 0, 4862, 4862, 3432, 2002, 1001, 429, 154, 44
Offset: 0

Views

Author

N. J. A. Sloane, Jan 28 2001

Keywords

Examples

			Triangle starts
  0;
  0,    1;
  0,    1,    1;
  0,    2,    2,    1;
  0,    5,    5,    3,    1;
  0,   14,   14,    9,    4,    1;
  0,   42,   42,   28,   14,    5,   1;
  0,  132,  132,   90,   48,   20,   6,   1;
  0,  429,  429,  297,  165,   75,  27,   7,  1;
  0, 1430, 1430, 1001,  572,  275, 110,  35,  8, 1;
  0, 4862, 4862, 3432, 2002, 1001, 429, 154, 44, 9, 1;
  ...
		

Crossrefs

See also the triangle in A009766. First 2 diagonals both give A000108, next give A000245, A002057.
The three triangles A059365, A106566 and A099039 are the same except for signs and the leading term.
Essentially the same as A033184.
The following are all versions of (essentially) the same Catalan triangle: A009766, A030237, A033184, A053121, A059365, A099039, A106566, A130020, A047072, A171567, A181645.

Programs

  • Magma
    /* as triangle */ [[[0] cat [Binomial(2*r-s-1, r-1)- Binomial(2*r-s-1, r): s in [1..r]]: r in [0..10]]]; // Vincenzo Librandi, Jan 09 2017
  • Mathematica
    Table[Binomial[2*r - s - 1, r - 1] - Binomial[2*r - s - 1, r], {r, 0, 10}, {s, 0, r}] // Flatten (* G. C. Greubel, Jan 08 2017 *)
  • PARI
    tabl(nn) = { print(0); for (r=1, nn, for (s=0, r, print1(binomial(2*r-s-1,r-1)-binomial(2*r-s-1,r), ", ");); print(););}  \\ Michel Marcus, Nov 01 2013
    

Formula

Essentially the same triangle as [0, 1, 1, 1, 1, 1, 1, ...] DELTA A000007, where DELTA is Deléham's operator defined in A084938, but the first term is T(0,0) = 0.

A181644 Eigentriangle for the Catalan triangle (c(x), xc(x)), A033184.

Original entry on oeis.org

1, 1, 1, 2, 1, 1, 6, 3, 1, 1, 22, 11, 4, 1, 1, 92, 46, 17, 5, 1, 1, 426, 213, 79, 24, 6, 1, 1, 2150, 1075, 399, 122, 32, 7, 1, 1, 11708, 5854, 2173, 665, 176, 41, 8, 1, 1, 68282, 34141, 12673, 3878, 1027, 242, 51, 9, 1, 1, 423948, 211974, 78683, 24075, 6373, 1502
Offset: 0

Views

Author

Paul Barry, Nov 03 2010

Keywords

Comments

First column is essentially A091768. Inverse of A181645.

Examples

			Triangle begins
  1,
  1, 1,
  2, 1, 1,
  6, 3, 1, 1,
  22, 11, 4, 1, 1,
  92, 46, 17, 5, 1, 1,
  426, 213, 79, 24, 6, 1, 1,
  2150, 1075, 399, 122, 32, 7, 1, 1,
  11708, 5854, 2173, 665, 176, 41, 8, 1, 1
		

Crossrefs

Showing 1-2 of 2 results.