OFFSET
1,2
COMMENTS
a(n) is the number of functions F from the powerset of {1, ..., n} to {-1, +1} with F(empty set) = +1 and satisfying the constraint: F({i} union S) != F({j} union S) => F(S) != F({i,j} union S) for any subset S and distinct i,j not in S.
LINKS
Tobias Boege, Jesse Selover, and Maksym Zubkov, Sign patterns of principal minors of real symmetric matrices, arXiv:2407.17826 [math.CO], 2024.
Richard F. Booth, Alexandre V. Borovik, Israel M. Gelfand, and Neil White, Oriented Lagrangian Matroids, European Journal of Combinatorics, 22(5) (2001), 639-656.
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Jesse Selover, Aug 12 2024
STATUS
approved