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A024311 Catacondensed simply-connected monopentapolyhexes. 1
0, 0, 1, 7, 30, 132, 559, 2416, 10483, 46072, 204155, 912779, 4110644, 18636572, 84985825, 389586145, 1794268460, 8298524480, 38527095859, 179487051589, 838820171722, 3931498431052, 18475618863389, 87036535974062, 410947146076475 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

LINKS

Table of n, a(n) for n=1..25.

S. J. Cyvin, B. N. Cyvin, J. Brunvoll, Zhang Fuji, Guo Xiaofeng, R. Tosic, Graph-theoretical studies on fluoranthenoids and fluorenoids: enumeration of some catacondensed systems, J. Molec. Struct. (Theochem), 285 (1993), 179-185.

FORMULA

a(n) = (1/2) * (A002212(n) - 2*A002212(n - 1) - A055879(n)). - Sean A. Irvine, Jun 26 2019

G.f.: (6*x^3 - 12*x^2 + 6*x + (2*x^2-3*x+1) * sqrt(1-x) * sqrt(1-5*x) - sqrt(1-x^2) * sqrt(1-5*x^2)) / (4*x*(x-1)). - Sean A. Irvine, Jun 26 2019

CROSSREFS

Cf. A007317, A046697.

Sequence in context: A037611 A171472 A220720 * A210100 A297080 A256981

Adjacent sequences:  A024308 A024309 A024310 * A024312 A024313 A024314

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, May 03 2000

EXTENSIONS

More terms from Sean A. Irvine, Jun 26 2019

STATUS

approved

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Last modified August 5 17:03 EDT 2021. Contains 346486 sequences. (Running on oeis4.)