macro
boot.janet on line 570, column 1
(seq head & body)
Similar to loop, but accumulates the loop body into an array and
returns that. See loop for details.
(seq [i :range [0 10] :when (odd? i)] (math/pow 2 i))
# => @[2 8 32 128 512]
# array with 2 to the power of all odd numbers smaller than 10