#/usr/bin/env bqn

TargetIndex ← { ((𝕨⊸=∧)/(↕≠))𝕩 }

•Show 2 TargetIndex 1‿5‿3‿2‿4‿2
•Show 6 TargetIndex 1‿2‿4‿3‿5
•Show 4 TargetIndex 5‿3‿2‿4‿2‿1