Formal target: Corpus.OEIS64313.conjecture
"Usually (perhaps always?) $\lfloor n^2 / (4\pi) - \pi / 12 \rfloor$ for a polygon of circumference $n$.
Exact formal statement
∀ (n : Nat),
LE.le.{0} 3 n →
Eq.{1} (Corpus.OEIS64313.a n)
(Int.floor.{0}
(HSub.hSub.{0, 0, 0}
(HDiv.hDiv.{0, 0, 0} (HPow.hPow.{0, 0, 0} (Nat.cast.{0} n) 2) (HMul.hMul.{0, 0, 0} 4 Real.pi))
(HDiv.hDiv.{0, 0, 0} Real.pi 12))).toNatThis target is a formal statement, not a proof of the problem.
Environment availability: available.