lcm &rest integers => least-common-multiple
integer—an integer.
least-common-multiple—a non-negative integer.
lcm returns the least common multiple of the integers.
If no integer is supplied, the integer 1 is returned.
If only one integer is supplied, the absolute value of that integer is returned.
For two arguments that are not both zero,
(lcm a b) == (/ (abs (* a b)) (gcd a b))
If one or both arguments are zero,
(lcm a 0) == (lcm 0 a) == 0
For three or more arguments,
(lcm a b c ... z) == (lcm (lcm a b) c ... z)
(lcm 10) => 10
(lcm 25 30) => 150
(lcm -24 18 10) => 360
(lcm 14 35) => 70
(lcm 0 5) => 0
(lcm 1 2 3 4 5 6) => 60
Should signal type-error if any argument is not an integer.