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A094610
Number of unlabeled 4-gonal 2-trees with n 4-gons.
2
1, 1, 1, 3, 8, 32, 141, 749, 4304, 26492, 169263, 1115015, 7507211, 51466500, 358100288, 2523472751, 17978488711, 129325796854, 938234533024, 6858551493579, 50478955083341, 373815860588360, 2783730088637429, 20835514668765200, 156675846789962554, 1183195305751233833
OFFSET
0,4
LINKS
G. Labelle, C. Lamathe and P. Leroux, Labeled and unlabeled enumeration of k-gonal 2-trees
CROSSREFS
Column k=4 of A340811.
Cf. A054581.
Sequence in context: A151541 A022563 A103939 * A064316 A009438 A321520
KEYWORD
nonn
AUTHOR
Vladeta Jovovic, Jun 06 2004
EXTENSIONS
Terms a(21) and beyond from Andrew Howroyd, May 09 2021
STATUS
approved