: ratio \ m n -- num denom
  tuck n:- n:1+ swap ;

\ one item in the row: n m
: pascitem \ n m -- n
	r@ swap
	ratio
	n:*/ n:round int
	dup . space ;

\ One row of Pascal's triangle
: pascline \ n --
	>r 1 int dup . space
	' pascitem
	1 r@ loop rdrop drop cr ;

\ Calculate the first 'n' rows of Pascal's triangle:
: pasc \ n
	' pascline 0 rot loop cr ;

15 pasc