Problem Statement

The   population count   is the number of   1s   (ones)   in the binary representation of a non-negative integer. Population count   is also known as:

For example,   5   (which is   101   in binary)   has a population count of   2.

Evil numbers   are non-negative integers that have an   even   population count. Odious numbers     are  positive integers that have an    odd   population count.

Let's start with the solution:

PopCount ← {(2|𝕩)+𝕊⍟×⌊𝕩÷2}
Odious ← 2|PopCount
Evil ← ¬Odious

_List ← {𝕩↑𝔽¨⊸/↕2×𝕩}
>⟨PopCount¨ 3⋆↕30, 
  Evil _List 30, 
  Odious _List 30⟩