19185257728domain: NAppears in sequencesa(n) = n^9 - n^8.at n=14A240932Start with a single cell at coordinates (0, 0, 0), then iteratively subdivide the grid into 3 X 3 X 3 cells and remove the cells whose sum of modulo 2 coordinates is 0 or 2; a(n) is the number of cells after n iterations.at n=9A285399