658137domain: NAppears in sequencesNumber of planar n X n X n binary triangular grids symmetric both under 120 degree rotation and reflection with no more than 7 ones in any 5 X 5 X 5 subtriangle.at n=15A153958Poincaré series for hyperbolic reflection group with Coxeter diagram o-(5)-o---o-(5)-o.at n=28A265048