.PS
# `Wheat.m4'
gen_init

boxwid = boxht

[ for j = 0 to 7 do {
    for i = 0 to 7 do {
      x = 2^(j+8*i)
      box fill_((i+j)%2) at (j*boxwid,-i*boxwid)
      k = ((i+j)%2==0); setrgb(k,k,k)
      if x < 10000 then { sprintf("\Large$%g$",x) at last box } \
      else { y = int(log(x))
        sprintf("{\Large$%g$}$\cdot 10^{%g}$",round_(x/(10^y)),y) at last box }
      resetrgb
      }
    }
  ]
box wid 8*boxwid ht 8*boxwid at last []

.PE