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A397927
Number of nonnegative integer matrices with a total of n rows and columns with each row sum and column sum nonzero and at most n.
2
1, 0, 2, 6, 122, 3300, 244502, 35533946, 13894204922, 11254924831650, 25931152822648922, 123129026842442598010, 1767099204159492194923140, 50472055186683607738951340430, 4642825806461056714820871058427887, 807990421462131145735305221452897896990
OFFSET
0,3
EXAMPLE
The a(2) = 2 matrices are the 1 X 1 matrices whose only value is 1 or 2.
The a(3) = 6 matrices are either 1 X 2 or 2 X 1:
[1] [1] [2] [1 1] [1 2] [2 1]
[1] [2] [1]
CROSSREFS
Main diagonal of A397926.
Cf. A397923 (up to row and column permutations).
Sequence in context: A039716 A164955 A060001 * A181316 A101753 A288185
KEYWORD
nonn,new
AUTHOR
Andrew Howroyd, Jul 16 2026
STATUS
approved