A Major 7#11, 1st inversion (C# in the bass)
Also written as Amaj7#11/C#.
Notes, from the bass up
C# (bass)EG#D#A
The same notes as A Major 7#11 (C#, E, G#, D# and A), rearranged so C# is the lowest note. Use it to move between chords with smaller jumps across the keyboard.