A038143 - OEIS

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A038143

Hexagonal cata-condensed helicenes with n cells (non-planar cata-fused benzenoid hydrocarbons).

5

0, 0, 0, 0, 0, 1, 5, 35, 200, 1121, 5919, 30509, 153187, 756825, 3688195, 17798388, 85223088, 405681703, 1922330483, 9077427515, 42751284417, 200947260030, 943181666824, 4422628241952

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,7

LINKS

Table of n, a(n) for n=1..24.

J. V. Knop, K. Szymanski, Ž. Jeričević, and N. Trinajstić, On the total number of polyhexes, Match, No. 16 (1984), 119-134.

CROSSREFS

Equals A002216-A038142. Cf. A018190.

Sequence in context: A241779 A265976 A123008 * A352404 A356391 A221578

Adjacent sequences: A038140 A038141 A038142 * A038144 A038145 A038146

KEYWORD

nonn,more,changed

AUTHOR

N. J. A. Sloane

EXTENSIONS

a(12)-a(15) from Andrei Zabolotskii, Feb 16 2023

a(16)-a(24) from Andrei Zabolotskii, Apr 02 2026

STATUS

approved