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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
2, 8, 44, 347, 3636 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

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.

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.

LINKS

Table of n, a(n) for n=1..5.

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

CROSSREFS

Sequence in context: A253949 A336545 A126101 * A157994 A002500 A002833

Adjacent sequences:  A308475 A308476 A308477 * A308479 A308480 A308481

KEYWORD

nonn,bref,more

AUTHOR

Bryan Bischof, May 29 2019

STATUS

approved

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Last modified January 25 21:23 EST 2021. Contains 340427 sequences. (Running on oeis4.)