multiples.hoon

:: The sum of multiples of 3 and 5 below 1000 is 233.168
:: Solved with `+multiples 1.000`

|=  n=@
=/  i=@  1
=/  sum=@  0
|-
?:  =(i n)
    sum
    ?:  ?|(=((mod i 3) 0) =((mod i 5) 0))
        $(i +(i), sum (add sum i))
        $(i +(i))