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A308478 a(n) = sum of the dimensions of the rational spans of all connected chord diagrams with n chords and any number m of link components, modulo all instances of the 4T-relation. 0

%I

%S 2,8,44,347,3636

%N a(n) = sum of the dimensions of the rational spans of all connected chord diagrams with n chords and any number m of link components, modulo all instances of the 4T-relation.

%C These numbers were generated as part of a proof of the dimensionality of the larger space of disconnected chord diagrams modulo 4T, and the code/combinatorics are provided in the paper.

%C At the time, computation was an issue but now it's likely the methods could be used to generate more terms. No generating function is known.

%H Bryan Bischof, Roman Kogan, David Yetter, <a href="https://arxiv.org/abs/0801.3253">On a basis for the framed link vector space spanned by chord diagrams</a>, arXiv: 0801.3253 [math.QA], 2008. Also Journal of Knot Theory and Its Ramifications. Vol. 18, No. 12, pp. 1663-1680 (2009).

%K nonn,bref,more

%O 1,1

%A _Bryan Bischof_, May 29 2019

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Last modified December 7 23:32 EST 2022. Contains 358671 sequences. (Running on oeis4.)