Nonagonal Number
A Figurate Number of the form 
, also called an Enneagonal Number. The first few are 1, 9, 24, 46,75, 111, 154, 204, ... (Sloane's A001106).
References
Sloane, N. J. A. SequenceA001106/M4604in ``An On-Line Version of the Encyclopedia of Integer Sequences.''http://www.research.att.com/~njas/sequences/eisonline.html and Sloane, N. J. A. and Plouffe, S.The Encyclopedia of Integer Sequences. San Diego: Academic Press, 1995.
- Quantic
- Quantifier
- Quantization Efficiency
- Quantum Chaos
- Quarter
- Quarter Squares Rule
- Quartet
- Quartic Curve
- Quartic Equation
- Quartic Reciprocity Theorem
- Quartic Surface
- Quartile
- Quartile Deviation
- Quartile Range
- Quartile Skewness Coefficient
- Quartile Variation Coefficient
- Quasiamicable Pair
- Quasiconformal Map
- Quasigroup
- Quasiperfect Number
- Quasiperiodic Function
- Quasiperiodic Motion
- Quasirandom Sequence
- Quasiregular Polyhedron
- Quasirhombicosidodecahedron