Write a mutating, replicating program
Jelly, 4 bytes

⁾ṘȮṘ


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(Equivalent to the 5-byte: “ṘȮ”Ṙ)

Exponentially spawns:

“ṘȮ”ṘȮ
“ṘȮ”ṘȮṘȮ
“ṘȮ”ṘȮ“ṘȮ”ṘȮṘȮ
“ṘȮ”ṘȮṘȮ“ṘȮ”ṘȮ“ṘȮ”ṘȮṘȮ
“ṘȮ”ṘȮ“ṘȮ”ṘȮṘȮ“ṘȮ”ṘȮṘȮ“ṘȮ”ṘȮ“ṘȮ”ṘȮṘȮ


Since Ṙ is a monadic atom which prints a Jelly representation of its input and then yields it's input, and Ȯ is a monadic atom which prints its input and yields it's input (neither printing any newlines), while “...” defines a list of characters. So each “ṘȮ”Ṙ prints “ṘȮ” and yields to the following Ȯ which prints ṘȮ and yields... a trailing Ȯ finally yields for the programs return value, which is implicitly printed, so the pattern will continue until resources no longer suffice.