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.

A368026 Array read by ascending antidiagonals: A(n, k) is the permanent of the n-th order Hankel matrix of Catalan numbers M(n) whose generic element is given by M(i,j) = A000108(i+j+k) with i,j = 0, ..., n-1.

Original entry on oeis.org

1, 1, 1, 3, 1, 1, 95, 9, 2, 1, 38057, 979, 53, 5, 1, 207372681, 1417675, 19148, 406, 14, 1, 15977248385955, 28665184527, 97432285, 490614, 3612, 42, 1, 17828166968924572623, 8325587326635565, 7146659536022, 8755482505, 14798454, 35442, 132, 1, 292842668371666277607183121, 35389363346700690999467, 7683122105385590481, 2318987094804471, 930744290905, 499114473, 372801, 429, 1
Offset: 0

Views

Author

Stefano Spezia, Dec 08 2023

Keywords

Examples

			The array begins:
      1,       1,        1,          1,            1, ...
      1,       1,        2,          5,           14, ...
      3,       9,       53,        406,         3612, ...
     95,     979,    19148,     490614,     14798454, ...
  38057, 1417675, 97432285, 8755482505, 930744290905, ...
  ...
		

Crossrefs

Cf. A000012 (n=0), A000108 (n=1).
Cf. A368012 (k=0), A368019 (k=1), A278843 (k=2), A368021 (k=3), A368022 (k=4), A368023 (k=5), A368024 (k=6).
Cf. A368025 (determinant), A368298 (diagonal).

Programs

  • Maple
    with(LinearAlgebra):
    C:= proc(n) option remember; binomial(2*n, n)/(n+1) end:
    A:= (n, k)-> `if`(n=0, 1, Permanent(Matrix(n, (i, j)-> C(i+j+k-2)))):
    seq(seq(A(d-k, k), k=0..d), d=0..8);  # Alois P. Heinz, Dec 20 2023
  • Mathematica
    A[n_,k_]:=If[n==0,1,Permanent[Table[CatalanNumber[i+j+k],{i,0,n-1},{j,0,n-1}]]]; Table[A[n-k,k],{n,0,8},{k,0,n}]//Flatten