A330134 - OEIS

%I #19 Dec 16 2019 08:58:46

%S 1,33,7555,13482049,186481694371,19733690332538577

%N Number of n X n (-1,0,1)-matrices with zero permanent.

%H Code Golf Stack Exchange, <a href="https://codegolf.stackexchange.com/q/196712/53884">Find the number of n-by-n (-1, 0, 1) matrices with zero permanent as quickly as possible</a>

%t a[n_] := Sum[Boole[Permanent[m] == 0], {m, Tuples[{-1, 0, 1}, {n, n}]}];

%Y Cf. A088672, A057981.

%K nonn,more,hard

%O 1,2

%A _Hongyang Cao_, Dec 02 2019

%E a(6) from _Peter J. Taylor_, Dec 16 2019