Heptagonal Number
A Figurate Number of the form 
. The first few are 1, 7, 18, 34, 55, 81, 112, ... (Sloane's A000566).The Generating Function for the heptagonal numbers is
References
Sloane, N. J. A. SequenceA000566/M4358in ``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.
- Augmented Pentagonal Prism
- Augmented Polyhedron
- Augmented Sphenocorona
- Augmented Triangular Prism
- Augmented Tridiminished Icosahedron
- Augmented Truncated Cube
- Augmented Truncated Dodecahedron
- Augmented Truncated Tetrahedron
- Aureum Theorema
- Aurifeuillean Factorization
- Ausdehnungslehre
- Authalic Latitude
- Autocorrelation
- Automorphic Function
- Automorphic Number
- Automorphism
- Automorphism Group
- Autonomous
- Autoregressive Model
- Auxiliary Circle
- Auxiliary Latitude
- Auxiliary Triangle
- Average
- Average Absolute Deviation
- Average Function