F# 13b9, 1st inversion (A# in the bass)
Also written as F#13b9/A#.
Notes, from the bass up
A# (bass)C#EGD#F#
The same notes as F# 13b9 (A#, C#, E, G, D# and F#), rearranged so A# is the lowest note. Use it to move between chords with smaller jumps across the keyboard.