cp's OEIS Frontend

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.

%I A358809 #14 Dec 07 2022 14:58:47
%S A358809 1,0,4,186,21823,4569098,1713573909
%N 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.
%e A358809 a(2) = 4:
%e A358809     [0, 2;
%e A358809      2, 1]
%e A358809 a(3) = 186:
%e A358809     [0, 4, 5;
%e A358809      4, 2, 3;
%e A358809      5, 3, 1]
%Y A358809 Cf. A000217, A351153, A351611.
%Y A358809 Cf. A358806 (minimal determinant), A358807 (maximal determinant), A358808 (minimal).
%K A358809 nonn,hard,more
%O A358809 0,3
%A A358809 _Stefano Spezia_, Dec 02 2022
%E A358809 a(5)-a(6) from _Hugo Pfoertner_, Dec 07 2022