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A039658 Related to enumeration of edge-rooted catafusenes. +0
2
0, 1, 2, 5, 8, 18, 28, 64, 100, 237, 374, 917, 1460, 3679, 5898, 15183, 24468, 64055, 103642, 275011, 446380, 1197616, 1948852, 5277070, 8605288, 23483743, 38362198, 105392983, 172423768, 476459938, 780496108, 2167743688, 3554991268 (list; graph; listen)
OFFSET

1,3

REFERENCES

S. J. Cyvin et al., Enumeration and classification of benzenoid systems. 32. Normal perifusenes with two internal vertices, J. Chem. Inform. Comput. Sci., 32 (1992), 532-540.

S. J. Cyvin et al., Enumeration and classification of certain polygonal systems...: annelated catafusenes, J. Chem. Inform. Comput. Sci., 34 (1994), 1174-1180.

FORMULA

G.f.: (1+x)[1-3x^2-sqrt(1-6x^2+5x^4)]/[2x^2(1-x)] (eq. (9) in Cyvin et al.)

CROSSREFS

Sequence in context: A086324 A073708 A024460 this_sequence A063675 A000943 A152006

Adjacent sequences: A039655 A039656 A039657 this_sequence A039659 A039660 A039661

KEYWORD

nonn

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

EXTENSIONS

More terms from Emeric Deutsch (deutsch(AT)duke.poly.edu), Mar 14 2004

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Last modified November 29 12:46 EST 2009. Contains 167659 sequences.


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