Extending this gets me to https://0xa000001/ which is flagged by chrome as all sorts of evil, even though it's just local address of my cable modem.

alternatively also http://0x01000001

Interestingly enough, I can't copy this to the clipboard on iOS. It automatically converts into http://1.0.0.1/.

You have to write it manually.

https://0x1000001

Also, https://1.1 and https://1.0.1

Doesn’t load for me with HTTP, only HTTPS. So your link doesn’t work for me.

For me it redirects.