C# 13th chord
C#13 chord for piano presented by keyboard diagrams.
Explanation: The C sharp thirteenth is a seven-note chord. Due to practical circumstances, some notes (as a suggestion fifth, ninth, and eleventh) are omitted and the chord is played inverted. The chord is sometimes played with both hands. The chord is often abbreviated as C#13.
Theory: The C# thirteenth chord is constructed by adding a third to an eleventh chord.
C#13

Notes: C# - F - G# - B - D# - F# - A#