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A018240 Rational knots with n crossings (up to mirroring). 5
1, 1, 2, 3, 7, 12, 24, 45, 91, 176, 352, 693, 1387, 2752 (list; graph; refs; listen; history; text; internal format)
OFFSET

3,3

COMMENTS

Identical through a(13) = 352 with Two-bridge Knots of crossing number n, in Table 1: Number of knots having two-bridged Conway polynomials, of Koseleff.

REFERENCES

E. Ernst and D. W. Sumners, "The growth of the number of prime knots", Math. Proc. Cambridge Philos. Soc. vol. 102 pages 303-315.

LINKS

Table of n, a(n) for n=3..16.

P. -V. Koseleff, D. Pecker, Conway polynomials of two-bridge links, Nov 27, 2010.

CROSSREFS

There is a conjecture that this is the same as A090596.

Sequence in context: A000630 A036538 A108742 * A090596 A054272 A129016

Adjacent sequences:  A018237 A018238 A018239 * A018241 A018242 A018243

KEYWORD

nice,nonn

AUTHOR

Alexander Stoimenow (stoimeno(AT)math.toronto.edu)

STATUS

approved

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Last modified April 23 04:43 EDT 2014. Contains 240909 sequences.