# [Jelly], 15 bytes µ<1ạḤðŒRṗAS$Þ⁸ị [Try it online!][TIO-j9k310nk] [Jelly]: https://github.com/DennisMitchell/jelly [TIO-j9k310nk]: https://tio.run/##ASsA1P9qZWxsef//wrU8MeG6oeG4pMOwxZJS4bmXQVMkw57igbjhu4v///8xMv8z "Jelly – Try It Online" 1-indexed. Inverse: AṀ×LŒRṗLAS$Þiµ:2NḂ}¡ [Try it online!][TIO-j9k31f0p] [TIO-j9k31f0p]: https://tio.run/##y0rNyan8/9/x4c6Gw9N9jk4Kerhzuo9jsMrheZmHtloZ@T3c0VR7aOH///@jDXUUgMggFgA "Jelly – Try It Online"