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.

A368012 a(n) 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) with i,j = 0, ..., n-1.

Original entry on oeis.org

1, 1, 3, 95, 38057, 207372681, 15977248385955, 17828166968924572623, 292842668371666277607183121, 71645110588632775032727941092738473, 263399284865064400938403105805219201386749363, 14653009564320804036813733761485114583670416021283903839, 12403293423772370760211339634714413308535752478944832963336911564521
Offset: 0

Views

Author

Stefano Spezia, Dec 08 2023

Keywords

Examples

			a(4) = 38057:
  1,  1,  2,   5;
  1,  2,  5,  14;
  2,  5, 14,  42;
  5, 14, 42, 132.
		

Crossrefs

Programs

  • Mathematica
    Join[{1},Table[Permanent[Table[CatalanNumber[i+j],{i,0,n-1},{j,0,n-1}]],{n,12}]]
  • PARI
    C(n) = binomial(2*n, n)/(n+1); \\ A000108
    a(n) = matpermanent(matrix(n, n, i, j, C(i+j-2))); \\ Michel Marcus, Dec 11 2023

Formula

Det(M(n)) = 1 (see Mays and Wojciechowski, 2000).