9-demicube

In geometry, a demienneract or 9-demicube is a uniform 9-polytope, constructed from the 9-cube, with alternated vertices removed. It is part of a dimensionally infinite family of uniform polytopes called demihypercubes. E. L. Elte identified it in 1912 as a semiregular polytope, labeling it as HM9 for a 9-dimensional half measure polytope. Coxeter named this polytope as 161 from its Coxeter diagram, with a ring on one of the 1-length branches, and Schläfli symbol or {3,36,1}. Cartesian coordinates for the vertices of a demienneract centered at the origin are alternate halves of the enneract: (±1,±1,±1,±1,±1,±1,±1,±1,±1) with an odd number of plus signs.