A358809 a(n) is the maximal permanent of an n X n symmetric matrix using all the integers from 0 to n*(n + 1)/2 - 1.

1, 0, 4, 186, 21823, 4569098, 1713573909

Offset: 0

Author

Stefano Spezia, Dec 02 2022

Keywords

• nonn
• hard
• more

Examples

			a(2) = 4:
    [0, 2;
     2, 1]
a(3) = 186:
    [0, 4, 5;
     4, 2, 3;
     5, 3, 1]
		

Crossrefs

Cf. A000217, A351153, A351611.

Cf. A358806 (minimal determinant), A358807 (maximal determinant), A358808 (minimal).

Extensions

a(5)-a(6) from Hugo Pfoertner, Dec 07 2022