login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A030525
Number of polyhexes of class PF2 with a particular symmetry.
10
0, 1, 2, 5, 10, 21, 41, 85, 167, 345, 680, 1421, 2823, 5953, 11902, 25341, 50993, 109409, 221372, 478189, 972346, 2112181, 4313451, 9415165, 19301199, 42303241, 87015978, 191398741, 394888368, 871297141, 1802488991, 3987998101, 8270169571, 18342194721
OFFSET
4,3
COMMENTS
See reference for precise definition.
Cyvin has incorrect a(13)=273 and a(14)=608 in Table III due to using incorrect values for A026298(13) and A026298(14) in Table II. - Sean A. Irvine, Apr 03 2020
LINKS
S. J. Cyvin, Zhang Fuji, B. N. Cyvin, Guo Xiaofeng, and J. Brunvoll, Enumeration and classification of benzenoid systems. 32. Normal perifusenes with two internal vertices, J. Chem. Inform. Comput. Sci., 32 (1992), 532-540.
KEYWORD
nonn
EXTENSIONS
a(13) and a(14) corrected and more terms from Sean A. Irvine, Apr 03 2020
STATUS
approved