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%I #16 Aug 17 2020 13:34:53
%S 0,0,4,42,436,5650,96544,2185610,65108236
%N Number of idempotent non-symmetric n X n (0,1)-matrices over the reals.
%C Off diagonal entries of an idempotent symmetric n X n (0,1)-matrix must be zero.
%F a(n) = A086922(n) - A000079(n).
%e a(2) = 4 because [1,1] [0,1] [0,0] [1,0]
%e [0,0], [0,1], [1,1], [1,0], are non-symmetric and idemponent.
%Y Cf. A000079, A086922.
%K nonn,more
%O 0,3
%A _Torlach Rush_, Jun 22 2020
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