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.

A200073 Coefficients of a generalized Jaco-Lucas polynomial (odd indices) read by rows.

Original entry on oeis.org

1, 4, 3, 11, 15, 5, 29, 56, 35, 7, 76, 189, 171, 66, 9, 199, 605, 715, 407, 110, 11, 521, 1872, 2730, 2054, 832, 169, 13, 1364, 5655, 9810, 9180, 4965, 1533, 245, 15, 3571, 16779, 33745, 37774, 25585, 10642, 2618, 340, 17, 9349, 49096, 112309, 146357, 119168, 62453, 20862, 4218, 456, 19
Offset: 0

Views

Author

N. J. A. Sloane, Nov 13 2011

Keywords

Comments

Alternating row sums seem to be 1. - F. Chapoton, Nov 09 2021

Examples

			Triangle begins:
1,
4, 3,
11, 15, 5,
29, 56, 35, 7,
76, 189, 171, 66, 9,
...
		

Crossrefs

Cf. A002878 (first column), A005408 (diagonal).

Programs

  • Maple
    A200073 := proc(n,k)
        (2*n+1)*add( binomial(2*n+1-j,j)*binomial(j,k)/(2*n+1-j),j=0..n) ;
    end proc:
    seq(seq(A200073(n,k),k=0..n),n=0..13) ; # R. J. Mathar, Nov 13 2011
  • Mathematica
    T[n_, k_] := Sum[(2n+1) Binomial[2n+1-j, j] Binomial[j, k]/(2n+1-j), {j, 0, n}];
    Table[T[n, k], {n, 0, 9}, {k, 0, n}] // Flatten (* Jean-François Alcover, Apr 02 2020 *)

Formula

T(n,k) = Sum_{j=0..n} (2n+1)*binomial(2n+1-j,j)*binomial(j,k)/(2n+1-j).