{ "id": "2010.06550", "version": "v1", "published": "2020-10-13T17:03:58.000Z", "updated": "2020-10-13T17:03:58.000Z", "title": "Connected Chord Diagrams and the Combinatorics of Asymptotic Expansions", "authors": [ "Ali Assem Mahmoud", "Karen Yeats" ], "categories": [ "math.CO", "hep-th" ], "abstract": "In this article we study an asymptotic expansion for $C_n$, the number of connected chord diagrams on $n$ chords. The expansion is obtained in earlier work by means of alien derivatives applied to the generating series of connected chord diagrams; we seek a combinatorial interpretation. The main outcome presented here is a new combinatorial interpretation for entry \\href{https://oeis.org/A088221}{A088221} of the OEIS. We will show that \\href{https://oeis.org/A088221}{A088221} counts pairs of connected chord diagrams (allowing empty diagrams). This gives a combinatorial interpretation for the part of the closed form of the asymptotic expansion of $C_n$.", "revisions": [ { "version": "v1", "updated": "2020-10-13T17:03:58.000Z" } ], "analyses": { "keywords": [ "connected chord diagrams", "asymptotic expansion", "combinatorial interpretation", "combinatorics", "empty diagrams" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }