[sqnguyen]

this is my perl golf version of the same series. You can probably can do something similar with js:

map$l+=(-1)$_/(1-$_2)4,1..<>;die$l

[NieDzejkob]

Doesn't work for me [0]. Perhaps HN messed it up somehow?

[0]: https://tio.run/##K0gtyjH9/z83sUAlR9tWQ9dQUyVeX8NQVyXeSNNEx1...

[sqnguyen]

I guess so... https://tio.run/##K0gtyjH9/z83sUAlR9tWQ9dQU0tLJV5fw1BXJV7LSF...

[mkl]

To post code, indent it with two spaces, or HN will turn asterisks into italics on/off.