Stamp Folding
The number of ways of folding a strip of stamps has several possible variants. Considering only positions of the hingesfor unlabeled stamps without regard to orientation of the stamps, the number of foldings is denoted 
. If the stampsare labeled and orientation is taken into account, the number of foldings is denoted 
. Finally, the number ofsymmetric foldings is denoted 
. The following table summarizes these values for the first
.
| | | |
| Sloane | Sloane's A001010 | Sloane's A001011 | Sloane's A000136 |
| 1 | 1 | 1 | 1 |
| 2 | 2 | 1 | 2 |
| 3 | 2 | 2 | 6 |
| 4 | 4 | 5 | 16 |
| 5 | 6 | 14 | 50 |
| 6 | 8 | 38 | 144 |
| 7 | 18 | 120 | 462 |
| 8 | 20 | 353 | 1392 |
| 9 | 56 | 1148 | 4536 |
| 10 | 48 | 3527 | 14060 |
References
Gardner, M. ``The Combinatorics of Paper-Folding.'' In Wheels, Life, and Other Mathematical Amusements. New York: W. H. Freeman, pp. 60-73, 1983. Ruskey, F. ``Information of Stamp Folding.'' http://sue.csc.uvic.ca/~cos/inf/perm/StampFolding.html. Sloane, N. J. A. A Handbook of Integer Sequences. Boston, MA: Academic Press, p. 22, 1973.
- Saalschütz's Theorem
- s-Additive Sequence
- Saddle
- Saddle-Node Bifurcation
- Saddle Point (Fixed Point)
- Saddle Point (Function)
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- Safarevich Conjecture
- Safe
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