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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.

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

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

Cf. A090596.

Sequence in context: A000630 A036538 A108742 * A090596 A054272 A129016

Adjacent sequences:  A018237 A018238 A018239 * A018241 A018242 A018243

KEYWORD

nice,more,nonn

AUTHOR

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

STATUS

approved

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Last modified September 3 03:33 EDT 2014. Contains 246369 sequences.