Are you sure about the first rule? It doesn't seem necessary according to https://oeis.org/A014575.
The problem is really fun.
cheating
Since I created the problem series and want the Functions I badge, I thought I'd provide the solution that incorporates vampire_factor and are_fangs. Not a great score, but readable!
Sorry, I mean the Magic Numbers badge.
Like it
18003 Solvers
271 Solvers
Compute a dot product of two vectors x and y
760 Solvers
1077 Solvers
Given a square and a circle, please decide whether the square covers more area.
388 Solvers
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