A373027 Number of (0,1)-matrices with sum of entries equal to 2*n or 2*n+1, no zero rows or columns, which are centrally symmetric.
1, 4, 32, 400, 6660, 138576, 3460464, 100821904, 3357239440
Offset: 0
Examples
The a(2) = 32 matrices with sum of entries equal to 4: [1 0 0 0] [0 0 0 1] [1 0 0 0] [0 0 0 1] [0 0 1 0] [0 1 0 0] [0 1 0 0] [0 1 0 0] [0 0 1 0] [0 0 1 0] [0 0 0 1] [1 0 0 0] [0 0 1 0] [0 0 1 0] [0 1 0 0] [0 1 0 0] [1 0 0 0] [0 0 0 1] [0 0 0 1] [1 0 0 0] [0 0 0 1] [1 0 0 0] [0 1 0 0] [0 0 1 0] . [0 1 0 0] [0 0 1 0] [1 0 0] [0 1 0] [0 1 0] [0 0 1] [0 0 0 1] [1 0 0 0] [0 1 0] [1 0 0] [0 0 1] [0 1 0] [1 0 0 0] [0 0 0 1] [0 1 0] [0 0 1] [1 0 0] [0 1 0] [0 0 1 0] [0 1 0 0] [0 0 1] [0 1 0] [0 1 0] [1 0 0] . [1 0] [0 1] [1 0] [0 1] [1] [1 0] [0 1] [0 1] [1 0] [1] [0 1] [1 0] [1 0] [0 1] [1] [0 1] [1 0] [0 1] [1 0] [1] . [1 0 0 0] [0 1 0 0] [0 0 1 0] [0 0 0 1] [0 1 0] [1 0] [0 1] [0 1 1 0] [1 0 0 1] [1 0 0 1] [0 1 1 0] [1 0 1] [1 1] [1 1] [0 0 0 1] [0 0 1 0] [0 1 0 0] [1 0 0 0] [0 1 0] [0 1] [1 0] . [1 1 0 0] [0 0 1 1] [1 0 1 0] [0 1 0 1] [1 1 0] [0 1 1] [1 1] [0 0 1 1] [1 1 0 0] [0 1 0 1] [1 0 1 0] [0 1 1] [1 1 0] [1 1] . [1 1 1 1]
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