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

LINKS

Table of n, a(n) for n=0..20.

FORMULA

G.f.: 2(1 + 1324z + 20495z^2 + 46360z^3 + 20495z^4 + 1324z^5 + z^6)/(1-z)^7.

MAPLE

a:=n->2*(5*n^2+5*n+1)^3: seq(a(n), n=0..28);

CROSSREFS

Sequence in context: A225221 A324426 A114067 * A002495 A242109 A078457

Adjacent sequences:  A109116 A109117 A109118 * A109120 A109121 A109122

KEYWORD

nonn,easy

AUTHOR

Emeric Deutsch, Jun 19 2005

STATUS

approved

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Last modified July 14 18:26 EDT 2020. Contains 335729 sequences. (Running on oeis4.)