FunctionClauseError is what I’d expect from iteraterefs if it was called with number < divisor. You likely need to define it for those inputs as well to pass Exercism’s tests.
General note: this isn’t going to do what you want. i = i + 1 rebinds the name i inside the do / end block but that value doesn’t escape or even make it to the next iteration.
Same thing for out = out <> elem(table, i) inside iteraterefs; the name out is bound to a new name but then the scope ends immediately.
My recommendation would be to forget completely about Enum.each for a little while; it is almost never the right solution in Elixir.
