OFFSET
1,2
COMMENTS
a(n) is the number of n X n matrices that neither row-consistent nor column-consistent (equivalently, has at least one column of zeros and at least one row of zeros).
LINKS
R. Duncan Luce, A Note on Boolean Matrix Theory, Proceedings of the American Mathematical Society 3 (1952), 382-388.
FORMULA
a(n) = Sum_{i=1..n} Sum_{j=1..n} (-1)^(i+j) * binomial(n,i) * binomial(n,j) * 2^((n-i)*(n-j)).
EXAMPLE
For n = 3, a(3) = 91 is the total number of 3 X 3 Boolean matrices with at least one column of zeros and one row of zeros.
MATHEMATICA
a[n_Integer?NonNegative] := Sum[Sum[(-1)^(i + j) Binomial[n, i] Binomial[n, j] 2^((n - i) (n - j)), {j, 1, n}], {i, 1, n}];
seq[n_Integer?NonNegative] := Table[a[k], {k, 1, n}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Courtney Gibbons, Jan 21 2026
STATUS
approved
