Your task is to create the shortest program (A) that outputs another program (B) with the most unique bytes, which in turn outputs the original program (A). Essentially, you are golfing one half of a pair of ouroboros programs (a.k.a. periodic iterating quine) and bowling the other half. A and B may be in different languages.

Rules and Scoring

Your final score is <number of unique bytes in B> / <number of bytes in A>. Highest score wins. It should be noted that the theoretical maximum score is 256.

• Program A must be at least one byte long


• Program B cannot consist entirely of no-ops, i.e. at least one character must affect the output in some way.


• 
  Standard rules of quines apply to both programs. Notably, error quines are not allowed in either case.

For the sake of answer format consistency, begin your answer with something like this:

# <Language for A> & <Language for B>, Score: <B score> / <A score> = <combined score>

Japt & Japt, Score: 255 / 38 = 6.71

Program A:

"iQ ²¯24

G²õ@i'#+Xd"iQ ²¯24

G²õ@i'#+Xd

Program B is over 8kB long, so long that the link breaks, so I won't paste the whole thing. Here's a sample:

#þ"iQ ²¯24

G²õ@i'#+Xd"iQ ²,#ÿ"iQ ²¯24

G²õ@i'#+Xd"iQ ²,#Ā"iQ ²¯24

G²õ@i'#+Xd"iQ ²

I couldn't find a way to get a NUL byte to work, which is why program B only has 255 unique characters. Program B essentially consists of 255 copies of a single program, where a single irrelevant byte is changed each time, and the first 254 executions are ignored.

For the explanation, I'll start with this simplified version of A so that the resulting B is easier to discuss.

"iQ ²¯23

3õ@i'#+Xd"iQ ²¯23

3õ@i'#+Xd

This program is based on the basic payload-capable Japt quine. The string at the start contains a duplicate of the rest of the program, iQ ² inserts a quote and duplicates to create a string representation of the entire program, and then ¯23 trims off itself and everything after it. The resulting string is a program that outputs Program A:

"iQ ²¯23

3õ@i'#+Xd"iQ ²

I will refer to this string as U.

The last line of A duplicates U a bunch of times with a small change each time. Specifically, for each number X in the range [1...3] it outputs "#c" + U where c is the character with charcode X. The default behavior of Japt is to output those strings with no quotation marks and separated by commas, so this is the output of our Simplified A:

#"iQ ²¯23

3õ@i'#+Xd"iQ ²,#"iQ ²¯23

3õ@i'#+Xd"iQ ²,#"iQ ²¯23

3õ@i'#+Xd"iQ ²

We'll call this Simplified B.

Simplified B has a simple structure, alternating between #c and U. Fortunately for this answer, each #c and U is treated as separated by a comma, and in this situation the behavior of that is everything except the very last U has no effect on the output. The only portion of Simplified B which affects the output is this:

"iQ ²¯23

3õ@i'#+Xd"iQ ²

Which is identical to U that we already know outputs Simplified A.

The only difference between Simplified A and Program A is that instead of generating copies for the range [1...3] the real program generates copies for the range [1...256]. That results in 256 versions of #c each of which has a different character, though the last version "Ā" is a multi-byte character so it doesn't add any unique bytes, but everything except the last U is still ignored.

Program A, Gol><>, 256/20 bytes = 12.8

"44XFL|r2ssl3%Q4s]|H

Try it online!

Program B, Gol><>

"44XFL|r2ssl3%Q4s]|H	



 !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[]^_`abcdefghijklmnopqrstuvwxyz{|}~€‚ƒ„…†‡ˆ‰Š‹ŒŽ‘’“”•–—˜™š›œžŸ ¡¢£¤¥¦§¨©ª«¬­®¯°±²³´µ¶·¸¹º»¼½¾¿ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖ×ØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõö÷øùúûüýþÿ

Try it online!

The program alternates between outputting itself followed by every byte and just outputting itself.

Explanation:

"            Wrapping string literal pushes the first line to the stack backwards

 44X         Push 256

    FL|      Push the range from 0 to 255

       r                  Reverse the stack

        2ss               Push a quote

           l3%            If the stack length is divisible by 3

              Q4s]|       Only take the top 20 characters

                   H      And output the stack