faro ← ∊∘⍉(2,2÷⍨≢)⍴⊢ count ← {⍺←⍵ ⋄ ⍺≡r←⍺⍺ ⍵:1 ⋄ 1+⍺∇r} (⊢,[1.5] (faro count ⍳)¨) 8 24 52 100 1020 1024 10000