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A330058 Number of non-isomorphic multiset partitions of weight n with at least one endpoint. 9

%I #11 Jan 16 2023 04:33:36

%S 0,1,2,7,21,68,214,706,2335,7968,27661,98366,357212,1326169,5027377,

%T 19459252,76850284,309531069,1270740646,5314727630,22633477157,

%U 98096319485,432490992805,1938762984374,8832924638252,40882143931620,192148753444380,916747097916418

%N Number of non-isomorphic multiset partitions of weight n with at least one endpoint.

%C The weight of a multiset partition is the sum of sizes of its parts. Weight is generally not the same as number of vertices.

%C An endpoint is a vertex appearing only once (degree 1).

%C Also the number of non-isomorphic multiset partitions of weight n with at least one singleton.

%H Andrew Howroyd, <a href="/A330058/b330058.txt">Table of n, a(n) for n = 0..50</a>

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Degree_(graph_theory)">Degree (graph theory)</a>

%F a(n) = A007716(n) - A302545(n). - _Andrew Howroyd_, Jan 15 2023

%e Non-isomorphic representatives of the a(1) = 1 through a(4) = 21 multiset partitions:

%e {1} {12} {122} {1222}

%e {1}{2} {123} {1233}

%e {1}{22} {1234}

%e {1}{23} {1}{222}

%e {2}{12} {12}{22}

%e {1}{2}{2} {1}{233}

%e {1}{2}{3} {12}{33}

%e {1}{234}

%e {12}{34}

%e {13}{23}

%e {2}{122}

%e {3}{123}

%e {1}{1}{23}

%e {1}{2}{22}

%e {1}{2}{33}

%e {1}{2}{34}

%e {1}{3}{23}

%e {2}{2}{12}

%e {1}{2}{2}{2}

%e {1}{2}{3}{3}

%e {1}{2}{3}{4}

%Y The case of set-systems is A330053 (singletons) or A330052 (endpoints).

%Y The complement is counted by A302545.

%Y Cf. A007716, A283877, A306005, A330054, A330055, A330059.

%K nonn

%O 0,3

%A _Gus Wiseman_, Nov 30 2019

%E Terms a(11) and beyond from _Andrew Howroyd_, Jan 15 2023

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Last modified April 18 20:26 EDT 2024. Contains 371781 sequences. (Running on oeis4.)