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A369285
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Number of connected binary matrices with n ones, no zero rows or columns, and distinct rows and columns.
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3
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1, 1, 0, 4, 12, 72, 522, 4386, 42360, 465792, 5697552, 77229216, 1145762400, 18485254536, 322206163200, 6033964218720, 120830927523240, 2576515514434920, 58285369894027440, 1394212928447354640, 35160926971256369400, 932396530226753051160, 25936228654879236020640
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OFFSET
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0,4
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LINKS
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EXAMPLE
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The a(3) = 4 matrices:
[1 1] [1 1] [1 0] [0 1]
[1 0] [0 1] [1 1] [1 1]
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PROG
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(PARI) \\ Q, ConnectedMats defined in A321588.
seq(n)={my(R=vectorv(n, m, Q(m, n, w->1 + y^w + O(y*y^n)))); for(i=2, #R, R[i] -= i*R[i-1]); Vec(1 + vecsum(vecsum(Vec(ConnectedMats(Mat(R))))))}
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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