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A109119
a(n) = 2(5n^2 + 5n + 1)^3.
0
2, 2662, 59582, 453962, 2060602, 6885902, 18787862, 44376082, 94091762, 183467702, 334568302, 577609562, 952759082, 1512116062, 2321871302, 3464647202, 5042017762, 7177208582, 10017976862, 13739671402, 18548472602
OFFSET
0,1
COMMENTS
Kekulé numbers for certain benzenoids.
REFERENCES
S. J. Cyvin and I. Gutman, Kekulé structures in benzenoid hydrocarbons, Lecture Notes in Chemistry, No. 46, Springer, New York, 1988 (p. 310).
FORMULA
G.f.: 2(1 + 1324z + 20495z^2 + 46360z^3 + 20495z^4 + 1324z^5 + z^6)/(1-z)^7.
a(n) = 2*A062786(n)^3. - R. J. Mathar, Jul 22 2022
MAPLE
a:=n->2*(5*n^2+5*n+1)^3: seq(a(n), n=0..28);
CROSSREFS
Sequence in context: A347654 A324426 A114067 * A002495 A353126 A242109
KEYWORD
nonn,easy
AUTHOR
Emeric Deutsch, Jun 19 2005
STATUS
approved