# [K (ngn/k)], <s>19</s> 13 bytes

    {+//2\x_!1+y}

[Try it online!][TIO-ji45ssd8]

[K (ngn/k)]: https://gitlab.com/n9n/k
[TIO-ji45ssd8]: https://tio.run/##y9bNS8/7/z/NqlpbX98opiJe0VC7svZ/WrSJtXnsfwA "K (ngn/k) – Try It Online"

`{` `}` is a function with arguments `x` and `y`

`!1+y` is the list 0 1 ... y

`x_` drops the first x elements

`2\` encodes each int as a list of binary digits of the same length (this is specific to ngn/k)

`+/` sum

`+//` sum until convergence; in this case sum of the sum of all binary digit lists