use experimental :cached; proto pascal(Int, Int) is cached {*} multi pascal(Int, 0) { 1 } multi pascal(Int $a, $ where * == $a) { 1 } multi pascal(Int $a, Int $b where * < $a) { pascal($a - 1, $b) + pascal($a - 1, $b - 1) } sub MAIN(Int :$row!, Int :$col!) { say pascal +$row, +$col }