Triangle Tiling
The total number of triangle (including inverted ones) in the above figures is given by
The first few values are 1, 5, 13, 27, 48, 78, 118, 170, 235, 315, 411, 525, 658, 812, 988, 1188, 1413, 1665, ... (Sloane's A002717).
References
Conway, J. H. and Guy, R. K. ``How Many Triangles.'' In The Book of Numbers. New York: Springer-Verlag, pp. 83-84, 1996.
Sloane, N. J. A. SequenceA002717/M3827in ``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.
- Tetrad
- Tetradecagon
- Tetradecahedron
- Tetradic
- Tetradyakis Hexahedron
- Tetraflexagon
- Tetragon
- Tetrahedral Coordinates
- Tetrahedral Graph
- Tetrahedral Group
- Tetrahedral Number
- Tetrahedral Surface
- Tetrahedroid
- Tetrahedron
- Tetrahedron 10-Compound
- Tetrahedron 5-Compound
- Tetrahedron Inscribing
- Tetrahemihexacron
- Tetrahemihexahedron
- Tetrakaidecagon
- Tetrakaidecahedron
- Tetrakis Hexahedron
- Tetranacci Number
- Tetrix
- Tetromino