gistfile1.txt

\ 2520 is the smallest number that can be divided by each of the
\ numbers from 1 to 10 without any remainder.

\ What is the smallest positive number that is evenly divisible by all
\ of the numbers from 1 to 20?

: divisible-by-upto? { n upto -- bool }
    0
    upto 1+ 1 ?do
        n i mod +
        dup 0 <> if leave endif
    loop
    0 =
;

: problem5
    0
    begin
        1+
        dup 20 divisible-by-upto?
    until
;

problem5 .