P ← |1 memo(
  Terms ← ⊂1+1\+♭⍉˜⊟+1⊸×2↘1⇡20
  ⨬(⨬(/+ ≡(P-) Terms¤|1)⊸=₁|0)⊸≤₀
)
P69 # Bigger results look like they've already lost precision.