A 13b9, 5th inversion (F# in the bass)
Also written as A13b9/F#.
Notes, from the bass up
F# (bass)AC#EGBb
The same notes as A 13b9 (F#, A, C#, E, G and Bb), rearranged so F# is the lowest note. Use it to move between chords with smaller jumps across the keyboard.