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.

A050165 Triangle read by rows: T(n,k) = M(2n+1,k,-1), 0 <= k <= n, n >= 0, array M as in A050144.

Original entry on oeis.org

1, 1, 1, 1, 3, 2, 1, 5, 9, 5, 1, 7, 20, 28, 14, 1, 9, 35, 75, 90, 42, 1, 11, 54, 154, 275, 297, 132, 1, 13, 77, 273, 637, 1001, 1001, 429, 1, 15, 104, 440, 1260, 2548, 3640, 3432, 1430, 1, 17, 135, 663, 2244, 5508, 9996, 13260, 11934
Offset: 0

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Comments

T is a mirror image of the array in A039599.

Examples

			Triangle begins:
  1;
  1,  1;
  1,  3,  2;
  1,  5,  9,   5;
  1,  7, 20,  28,  14;
  1,  9, 35,  75,  90,  42;
  1, 11, 54, 154, 275, 297, 132;
		

Crossrefs

Formula

Triangle T(n, k) read by rows; given by [1, 0, 0, 0, 0, 0, 0, 0, ...] DELTA [1, 1, 1, 1, 1, 1, 1, 1, 1, ...] where DELTA is the operator defined in A084938. T(n, k) = C(2n, k)*(2n-2k+1)/(2n-k+1). - Philippe Deléham, Dec 07 2003
Sum_{k=0..min(m, n)} T(m, m-k)*T(n, n-k) = A000108(m+n); A000108: Catalan numbers. - Philippe Deléham, Dec 30 2003
T(n, k) = 0 if n < k, T(n, n)= A000108(n) and for n > k: T(n, k) = Sum_{j=0..k} T(n-1-j, k-j)*A000108(j+1). - Philippe Deléham, Feb 03 2004
T(n,k)= Sum_{j>=0} (-1)^(n-j)*A094385(n,j)*binomial(j,k). - Philippe Deléham, May 05 2007
T(2n,n) = A126596(n). - Philippe Deléham, Nov 23 2011