A358808 a(n) is the minimal permanent of an n X n symmetric matrix using all the integers from 0 to n*(n + 1)/2 - 1.

1, 0, 1, 33, 2425, 357046, 92052610

Offset: 0

Author

Stefano Spezia, Dec 02 2022

Keywords

• nonn
• hard
• more

Examples

			a(2) = 1:
    [0, 1;
     1, 2]
a(3) = 33:
    [0, 1, 2;
     1, 3, 4;
     2, 4, 5]
a(4) = 2425:
  [0, 2, 3, 1;
   2, 8, 7, 4;
   3, 7, 9, 6;
   1, 4, 6, 5]
		

Crossrefs

Cf. A000217, A351153, A351610.

Cf. A358806 (minimal determinant), A358807 (maximal determinant), A358809 (maximal).

Extensions

a(4) corrected and a(5)-a(6) from Hugo Pfoertner, Dec 07 2022