cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-3 of 3 results.

A002864 Number of alternating prime knots with n crossings.

Original entry on oeis.org

0, 0, 1, 1, 2, 3, 7, 18, 41, 123, 367, 1288, 4878, 19536, 85263, 379799, 1769979, 8400285, 40619385, 199631989, 990623857, 4976016485, 25182878921, 128564665125
Offset: 1

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Author

Keywords

Comments

Ortho Flint Smith and Stuart Rankin, with coding by Peter de Vries, calculated a(21) = 990623857 on a Compaq ES 45 in just under 14 hours on Jul 01 2003 (Canada Day).

References

  • See A002863 for many other references and links.
  • J. H. Conway, An enumeration of knots and links and some of their algebraic properties. 1970. Computational Problems in Abstract Algebra (Proc. Conf., Oxford, 1967) pp. 329-358 Pergamon, Oxford.
  • J. Hoste, M. B. Thistlethwaite and J. Weeks, The First 1,701,936 Knots, Math. Intell., 20, 33-48, Fall 1998.
  • Stuart Rankin, Ortho Flint Smith and John Schermann, Enumerating the Prime Alternating Knots, Part I, Journal of Knot Theory and its Ramifications, 13 (2004), 57-100.
  • Stuart Rankin, Ortho Flint Smith and John Schermann, Enumerating the Prime Alternating Knots, Part II, Journal of Knot Theory and its Ramifications, 13 (2004), 101-149.
  • N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
  • P. G. Tait, Scientific Papers, Cambridge Univ. Press, Vol. 1, 1898, Vol. 2, 1900, see Vol. 1, p. 345.
  • M. B. Thistlethwaite, personal communication.
  • M. B. Thistlethwaite, Knot tabulations and related topics. Aspects of topology, 1-76, London Math. Soc. Lecture Note Ser., 93, Cambridge Univ. Press, Cambridge-New York, 1985.

Crossrefs

Cf. A002863, A049344. A diagonal of A059739.

Extensions

Terms from Hoste et al. added by Eric W. Weisstein; further terms from M. B. Thistlethwaite, Feb 10 2001
a(20) found by Ortho Flint Smith and Stuart Rankin (srankin(AT)uwo.ca), with coding done by Peter De Vries, Jun 26 2003
Ortho Flint Smith and Stuart Rankin, with coding by Peter de Vries, calculated a(22) = 4976016485 on an Intel Xeon 2.8ghz in 41.5 hours on Jul 07 2003
Ortho Flint and Stuart Rankin, with coding by Peter de Vries, calculated a(23) = 25182878921 on a Compaq ES 45 in 228 hours, finishing on Mar 14 2004
a(24) from Bruce Fontaine's table (produced by him together with Stuart Rankin and Ortho Flint in 2007) added by Andrey Zabolotskiy, Jun 08 2022

A086771 Prime links (not necessarily connected knots) with n crossings.

Original entry on oeis.org

0, 1, 1, 2, 3, 9, 16, 50, 132, 452, 1559
Offset: 1

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Author

Steven Finch, Aug 02 2003

Keywords

References

  • D. J. A. Welsh, On the number of knots and links, Sets, Graphs and Numbers (Budapest, 1991) 713-718, Colloq. Math. Soc. Janos Bolyai, 60, North-Holland, Amsterdam, 1992.

Crossrefs

A059739 Triangle T(n,k), n >= 1, giving number of prime unoriented alternating links with n crossings and k components.

Original entry on oeis.org

0, 0, 1, 1, 1, 1, 2, 1, 3, 3, 2, 7, 6, 1, 18, 14, 6, 1, 41, 42, 12, 1, 123, 121, 43, 9, 1, 367, 384, 146, 17, 1, 1288, 1408, 500, 100, 11, 1, 4878, 5100, 2074, 341, 23, 1, 19536, 21854, 8206, 1556, 181, 13, 1, 85263, 92234, 37222, 7193, 653, 29, 1, 379799, 427079, 172678, 33216, 3885, 301, 16, 1, 1769979, 2005800, 829904, 173549, 19122, 1129, 36, 1, 8400285, 9716848, 4194015, 876173, 105539, 8428, 471, 19, 1, 40619385, 48184018, 21207695, 4749914, 599433, 43513, 1813, 43, 1
Offset: 0

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Author

N. J. A. Sloane, Feb 10 2001

Keywords

Comments

A link is a not necessarily connected knot. Apart from the initial rows, the n-th row contains floor(n/2) terms.

Examples

			First few rows of irregular triangle:
   0
   0  1
   1
   1  1
   2  1
   3  3  2
   7  6  1
  18 14  6 1
  41 42 12 1
  ...
		

References

  • Ortho Flint, Bruce Fontaine and Stuart Rankin, The master array of a prime alternating link, preprint, 2007

Crossrefs

First column gives numbers of knots, A002864. Second column gives A059741. Row sums give A049344.

Extensions

Terms for the 20-, 21-, 22- and 23-crossing prime alternating links (see the b-file) added Nov 03 2007 by Stuart Rankin, Ortho Flint and Bruce Fontaine
Trailing 0 in row for n=2 removed by N. J. A. Sloane, Nov 21 2007
Showing 1-3 of 3 results.