sequences.extras: fix map-index!
sequences.extras: fix map-index!

tgunr/factor,tgunr/factor,mrjbq7/factor,tgunr/factor,tgunr/factor,factor/factor,factor/factor,factor/factor,mrjbq7/factor,mrjbq7/factor,mrjbq7/factor,factor/factor,tgunr/factor,mrjbq7/factor,factor/factor,factor/factor,tgunr/factor,mrjbq7/factor