References
- Banderier , C. , Bousquet-Mélou , M. , Denise , A. , Flajolet , P. , Gardy , D. and Gouyou-Beauchamps , D. 2002 . Generating functions for generating trees. Formal power series and algebraic combinatorics (Barcelona, 1999) . Discrete Mathamathics , 246 ( 1–3 ) : 29 – 55 .
- Sloane , N.J.A. and Plouffe , S. 1995 . The Encyclopedia of Integer Sequences , New York : Academic Press .