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.

A368021 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+3) with i,j = 0, ..., n-1.

Original entry on oeis.org

1, 5, 406, 490614, 8755482505, 2318987094804471, 9179129956137993425772, 546580120389987275414413168012, 492460174883711250780962744103403975159, 6747075036368337341936435881321217868978170152215, 1411689504898999110533224343869931312130954127737962059963934
Offset: 0

Views

Author

Stefano Spezia, Dec 08 2023

Keywords

Examples

			a(4) = 8755482505:
    5,  14,  42,   132;
   14,  42, 132,   429;
   42, 132, 429,  1430;
  132, 429, 1430, 4862.
		

Crossrefs

Programs

  • Mathematica
    Join[{1},Table[Permanent[Table[CatalanNumber[i+j+3],{i,0,n-1},{j,0,n-1}]],{n,10}]]
  • PARI
    C(n) = binomial(2*n, n)/(n+1); \\ A000108
    a(n) = matpermanent(matrix(n, n, i, j, C(i+j+1))); \\ Michel Marcus, Dec 11 2023

Formula

Det(M(n)) = A000330(n+1) (see Mays and Wojciechowski, 2000).