2 deleted 9 characters in body

Brain-Flak, 74 + 3 = 77 bytes

(((((()()()){}){}){}){})((()()()()()<>){})<>([]){({}[()]<(({})<>)<>>)}{}<>


Try it online!

Try it doubled and tripled.

Explanation

(((((()()()){}){}){}){}) # push 48 ("0") onto first stack
((()()()()()<>){})       # push 10 (\n) onto second stack
<>([]){({}[()]<          # a number of times equal to the height of the first stack:
(({})<>)<>             #   copy the top of the first stack to the second stack


The break point is in the middle of the <> in the "push 10" section. Breaking this up will leave a 5 on the third stack until we reach the corresponding second half, at which point pushing 10 will resume right where it left off.

While it is possible to push a printable ASCII value (space) in 22 bytes, this would make the central <> be executed after pushing 5. By adding two more bytes, I was able to move the <> so that all of the progress toward pushing 10 was on the third stack. As a bonus, this also made the resulting square more aesthetically pleasing.

Brain-Flak, 74 + 3 = 77 bytes

(((((()()()){}){}){}){})((()()()()()<>){})<>([]){({}[()]<(({})<>)<>>)}{}<>


Try it online!

Try it doubled and tripled.

Explanation

(((((()()()){}){}){}){}) # push 48 ("0") onto first stack
((()()()()()<>){})       # push 10 (\n) onto second stack
<>([]){({}[()]<          # a number of times equal to the height of the first stack:
(({})<>)<>             #   copy the top of the first stack to the second stack


The break point is in the middle of the <> in the "push 10" section. Breaking this up will leave a 5 on the third stack until we reach the corresponding second half, at which point pushing 10 will resume right where it left off.

While it is possible to push a printable ASCII value (space) in 22 bytes, this would make the central <> be executed after pushing 5. By adding two more bytes, I was able to move the <> so that all of the progress toward pushing 10 was on the third stack. As a bonus, this also made the resulting square more aesthetically pleasing.

Brain-Flak, 74 bytes

(((((()()()){}){}){}){})((()()()()()<>){})<>([]){({}[()]<(({})<>)<>>)}{}<>


Try it online!

Try it doubled and tripled.

Explanation

(((((()()()){}){}){}){}) # push 48 ("0") onto first stack
((()()()()()<>){})       # push 10 (\n) onto second stack
<>([]){({}[()]<          # a number of times equal to the height of the first stack:
(({})<>)<>             #   copy the top of the first stack to the second stack


The break point is in the middle of the <> in the "push 10" section. Breaking this up will leave a 5 on the third stack until we reach the corresponding second half, at which point pushing 10 will resume right where it left off.

While it is possible to push a printable ASCII value (space) in 22 bytes, this would make the central <> be executed after pushing 5. By adding two more bytes, I was able to move the <> so that all of the progress toward pushing 10 was on the third stack. As a bonus, this also made the resulting square more aesthetically pleasing.

1

Brain-Flak, 74 + 3 = 77 bytes

(((((()()()){}){}){}){})((()()()()()<>){})<>([]){({}[()]<(({})<>)<>>)}{}<>


Try it online!

Try it doubled and tripled.

Explanation

(((((()()()){}){}){}){}) # push 48 ("0") onto first stack
((()()()()()<>){})       # push 10 (\n) onto second stack
<>([]){({}[()]<          # a number of times equal to the height of the first stack:
(({})<>)<>             #   copy the top of the first stack to the second stack

The break point is in the middle of the <> in the "push 10" section. Breaking this up will leave a 5 on the third stack until we reach the corresponding second half, at which point pushing 10 will resume right where it left off.
While it is possible to push a printable ASCII value (space) in 22 bytes, this would make the central <> be executed after pushing 5. By adding two more bytes, I was able to move the <> so that all of the progress toward pushing 10 was on the third stack. As a bonus, this also made the resulting square more aesthetically pleasing.