[Tautology]

Same with 69 stars, must be a mathematical error not a actual arrangement problem.

[zck]

You could have uneven rows for 69:

  * * * * * * * * * 
   * * * * * * * * 
    * * * * * * * 
    * * * * * * * 
    * * * * * * * 
    * * * * * * * 
    * * * * * * * 
   * * * * * * * * 
  * * * * * * * * *

(Copied from my reddit comment: http://www.reddit.com/r/math/comments/cd6v6/a_mathematician_...)