SignedSubset
A carrier domain from the domains catalogue; the signature is its storage shape. What is known about it elsewhere is mostly recorded against the collections that enumerate it, and says so.
A carrier domain: the nominal type this object is stored and dispatched as.
OEIS
A000244via SignedSubsetsSageMathsage.geometry.polyhedron.library.polytopes.cross_polytope(dim)via CrossPolytopeSignedSubset: tuple<list<integer>, integer>