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A172441 Number of prime knots up to nine crossings with determinant 2n+1 and signature 2. 5
0, 1, 0, 2, 0, 2, 0, 3, 0, 2, 0, 4, 0, 5, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

Adapted from Figure 6.6. The prime knots up to nine crossings separated by signature and determinant, p. 146, Cromwell. Second column of A172184.

REFERENCES

Peter R. Cromwell, Knots and Links, Cambridge University Press, November 15, 2004.

LINKS

Table of n, a(n) for n=0..29.

EXAMPLE

a(1) = 1 because the only prime knot with determinant 2*1+1=3 and s=2 is 3_1, the left-handed trefoil.

a(3) = 2 because the only prime knots with determinant 2*3+1=7 and s=2 are 5_2 and 9_42.

CROSSREFS

A002863, A172184, A172293.

Sequence in context: A301979 A183063 A318979 * A053399 A322996 A242096

Adjacent sequences:  A172438 A172439 A172440 * A172442 A172443 A172444

KEYWORD

nonn

AUTHOR

Jonathan Vos Post, Nov 20 2010

STATUS

approved

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Last modified April 8 15:37 EDT 2020. Contains 333314 sequences. (Running on oeis4.)