# J, 10 bytes, score = 0.9 (9/10) ([cracked by Dennis](http://codegolf.stackexchange.com/a/89057/48934))

    *2%~3<:@*]

Computes [A000326](http://oeis.org/A000326).

This one should be easy.

[Online interpreter](http://tryj.tk/).

[Quickref](http://code.jsoftware.com/wiki/NuVoc).