Racah - Wigner quantum 6j Symbols, Ocneanu Cells for AN diagrams, and   quantum groupoids
  We relate quantum 6J symbols of various types (quantum versions of Wigner and Racah symbols) to Ocneanu cells associated with AN Dynkin diagrams. We check explicitly the algebraic structure of the associated quantum groupoids and analyze several examples (A3, A4). Some features relative to cells associated with more general ADE diagrams are also discussed. 
Robert Coquereaux