# [GolfScript], 25 bytes
Not that short but at least it works.

    ~[1]*{.p.2/{{+}*}%\,(}do;

[Try it online!][TIO-k57vmn1z]

[GolfScript]: http://www.golfscript.com/golfscript/
[TIO-k57vmn1z]: https://tio.run/##S8/PSStOLsosKPn/vy7aMFarWq9Az0i/ulq7VqtWNUZHozYl3/r/f0MA "GolfScript – Try It Online"