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A330134
Number of n X n (-1,0,1)-matrices with zero permanent.
1
1, 33, 7555, 13482049, 186481694371, 19733690332538577
OFFSET
1,2
MATHEMATICA
a[n_] := Sum[Boole[Permanent[m] == 0], {m, Tuples[{-1, 0, 1}, {n, n}]}];
CROSSREFS
Sequence in context: A232365 A183551 A114071 * A210069 A316777 A057981
KEYWORD
nonn,more,hard
AUTHOR
Hongyang Cao, Dec 02 2019
EXTENSIONS
a(6) from Peter J. Taylor, Dec 16 2019
STATUS
approved