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A086825
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Number of knots (prime or composite) with n crossings.
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2
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OFFSET
| 0,6
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LINKS
| S. R. Finch, Knots, links and tangles
Eric Weisstein's World of Mathematics, Knot
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EXAMPLE
| a(7)=8 since we have 7 prime knots and one composite knot (the connected sum 3_1#4_1 of the trefoil knot 3_1 and the figure eight knot 4_1). Note that 3_1*#4_1=3_1#4_1, where * denotes mirror image because 4_1 is achiral. a(8)=25 since we have 21 prime knots and four composites (3_1#5_1, 3_1#5_2, 3_1*#5_1 and 3_1*#5_2).
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CROSSREFS
| Cf. A002863.
Sequence in context: A088144 A100501 A142869 * A192476 A093365 A128600
Adjacent sequences: A086822 A086823 A086824 * A086826 A086827 A086828
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KEYWORD
| nonn
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AUTHOR
| S. R. Finch (Steven.Finch(AT)inria.fr), Aug 07 2003
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