OFFSET
0,4
COMMENTS
A set-system is a finite set of finite nonempty sets of positive integers. An singleton is an edge of size 1. The weight of a set-system is the sum of sizes of its parts. Weight is generally not the same as number of vertices.
LINKS
FORMULA
EXAMPLE
Non-isomorphic representatives of the a(1) = 1 through a(5) = 14 multiset partitions:
{1} {1}{2} {1}{12} {1}{123} {1}{1234}
{1}{23} {1}{234} {1}{2345}
{1}{2}{3} {1}{2}{12} {1}{12}{13}
{1}{2}{13} {1}{12}{23}
{1}{2}{34} {1}{12}{34}
{1}{2}{3}{4} {1}{2}{123}
{1}{2}{134}
{1}{2}{345}
{1}{23}{45}
{2}{13}{14}
{1}{2}{3}{12}
{1}{2}{3}{14}
{1}{2}{3}{45}
{1}{2}{3}{4}{5}
MATHEMATICA
A[s_Integer] := With[{s6 = StringPadLeft[ToString[s], 6, "0"]}, Cases[ Import["https://oeis.org/A" <> s6 <> "/b" <> s6 <> ".txt", "Table"], {_, _}][[All, 2]]];
A283877 = A@283877;
A306005 = A@306005;
a /@ Range[0, 50] (* Jean-François Alcover, Feb 09 2020 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Nov 30 2019
STATUS
approved