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A086826
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Number of nonsplittable links (prime or composite) with n crossings.
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0
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OFFSET
| 0,5
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COMMENTS
| A link L is splittable if we can embed a plane in R^3, disjoint from L, that separates one or more components of L from other components of L. Otherwise L is nonsplittable.
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LINKS
| S. R. Finch, Knots, links and tangles
Eric Weisstein's World of Mathematics, Splittable Link
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EXAMPLE
| a(5)=4 since we have 2 prime knots, as well as the Whitehead link; and the trefoil knot linked with a circle.
a(6)=15 since we have 3 prime knots, as well as 2 composite knots (the square & granny knots); 6 prime links; a chain of four circles simply-intertwined; four circles simply-intertwined in the shape of a "T"; three circles, two doubly-intertwined and two simply-intertwined; and the figure-eight knot linked with a circle.
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CROSSREFS
| Cf. A086771.
Sequence in context: A081714 A117718 A176857 * A130409 A157351 A071167
Adjacent sequences: A086823 A086824 A086825 * A086827 A086828 A086829
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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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