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.

A254632 Triangle read by rows, T(n, k) = 4^n*[x^k]hypergeometric([3/2, -n], [3], -x), n>=0, 0<=k<=n.

Original entry on oeis.org

1, 4, 2, 16, 16, 5, 64, 96, 60, 14, 256, 512, 480, 224, 42, 1024, 2560, 3200, 2240, 840, 132, 4096, 12288, 19200, 17920, 10080, 3168, 429, 16384, 57344, 107520, 125440, 94080, 44352, 12012, 1430, 65536, 262144, 573440, 802816, 752640, 473088, 192192, 45760, 4862
Offset: 0

Views

Author

Peter Luschny, Feb 03 2015

Keywords

Examples

			[   1]
[   4,     2]
[  16,    16,     5]
[  64,    96,    60,    14]
[ 256,   512,   480,   224,    42]
[1024,  2560,  3200,  2240,   840,  132]
[4096, 12288, 19200, 17920, 10080, 3168, 429]
		

Crossrefs

Programs

  • Maple
    h := n -> simplify(hypergeom([3/2, -n], [3], -x)):
    seq(print(seq(4^n*coeff(h(n), x, k), k=0..n)), n=0..9);
  • Mathematica
    T[n_, k_] := 4^(n-k) Binomial[n, k] CatalanNumber[k+1];
    Table[T[n, k], {n, 0, 8}, {k, 0, n}] (* Jean-François Alcover, Jun 28 2019 *)
  • Sage
    A254632 = lambda n,k: (4)^(n-k)*binomial(n,k)*catalan_number(k+1)
    for n in range(7): [A254632(n,k) for k in (0..n)]

Formula

T(n,0) = A000302(n).
T(n,n) = A000108(n+1).
T(n,1) = A002699(n) for n>=1.
T(n,n-1) = A128650(n+2) for n>=1.
T(2*n,n) = A254633(n).
T(n,k) = 4^(n-k)*C(n,k)*Catalan(k+1).
sum(k=0..n, T(n,k)) = A025230(n+2).