to bell.numbers :max.n
  make "a (array :max.n 0)
  make "n 0
  make "ubound.a :max.n - 1
  for [i 0 :ubound.a] [setitem :i :a 0]
  setitem 0 :a 1
  type "|B(|
  type form :n 2 0
  type "|) = |
  print form item 0 :a 9 0
  while [:n < :max.n] ~
   [setitem :n :a item 0 :a
    for [j :n 1 -1] ~
     [setitem :j - 1 :a (item :j - 1 :a) + (item :j :a)]
    make "n :n + 1
    type "|B(|
    type form :n 2 0
    type "|) = |
    print form item 0 :a 9 0]
  erase [[] [a] []]
end