Solution to slow for kata 54d496788776e49e6b00052f

Sum_of_divided.ex

defmodule Sumofdivided do

  def sum_of_divided(lst) do
    table = :ets.new(:results, [{:write_concurrency, true}, :public, :ordered_set])
    
    lst
    |> Task.async_stream(&insert_divs(&1, table), timeout: :infinity, ordered: false)
    |> Stream.run()
    
    :ets.tab2list(table)
  end
  
  defp insert_divs(n, table) do
    n
    |> prime_factors(2, [])
    |> Enum.each(fn prime ->
      :ets.update_counter table, prime, {2, n}, {0, 0}
    end)
  end
  
  
  defp prime_factors(1, _, acc), do: acc
  defp prime_factors(-1, _, acc), do: acc
  defp prime_factors(n, divi, acc) when rem(n, divi) == 0,  do: prime_factors(divide_all(n, divi), divi + 1, [divi | acc])
  defp prime_factors(n, divi, acc), do: prime_factors(n, divi + 1, acc)
  
  defp divide_all(n, m) when rem(n, m) == 0, do: divide_all(div(n, m), m)
  defp divide_all(n, _), do: n
end