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A373915
Determinants of symmetric real {0,1}-matrices of order 9 that only occur as positive values.
3
89, 94, 95, 97, 98, 99, 101, 102, 105, 110, 116, 125, 144
OFFSET
1,1
COMMENTS
The non-occurrence of the corresponding negative determinants ​​causes the difference A089472(9) - A118985(9) = 227 - 214 = 13.
A similar situation already occurs for 7 X 7 matrices, where the 3 determinant values -20, -24, -32 only occur with negative signs.
CROSSREFS
KEYWORD
nonn,fini,full
AUTHOR
Hugo Pfoertner, Jun 23 2024
STATUS
approved