

A358243


Number of nregular, N_0weighted pseudographs on 2 vertices with total edge weight 3, up to isomorphism.


6



1, 4, 9, 15, 21, 28, 34, 41, 47, 54, 60, 67, 73, 80, 86, 93, 99, 106, 112, 119, 125, 132, 138, 145, 151, 158, 164, 171, 177, 184, 190, 197, 203, 210, 216, 223, 229, 236, 242, 249, 255, 262, 268, 275, 281, 288, 294, 301, 307, 314, 320, 327, 333, 340, 346, 353
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OFFSET

1,2


COMMENTS

Pseudographs are finite graphs with undirected edges without identity, where parallel edges between the same vertices and loops are allowed.


LINKS



FORMULA

Apparently a(n) = A258589(n2) + 2 for n>= 4, i.e., terms satisfy linear recurrence a(n) = a(n1) + a(n2)  a(n3) for n>=7.  Hugo Pfoertner, Dec 02 2022


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



