OFFSET
7,1
REFERENCES
D. B. West, Introduction to Graph Theory, 2nd ed., Prentice-Hall, NJ, 2001, p. 205.
LINKS
R. Balakrishnan, S. F. Raj, The Wiener number of powers of the Mycielskian, Discussiones Math. Graph Theory, 30, 2010, 489-498 (see Theorem 2.1).
M. Eliasi, G.Raeisi, B. Taeri, Wiener index of some graph operations, Discrete Appl. Math., 160, 2012, 1333-1344 (see Example 2.5).
Index entries for linear recurrences with constant coefficients, signature (3,-3,1).
FORMULA
a(n) = 6n^2 - 13n.
G.f.: x^7*(203 - 329*x + 138*x^2)/(1 - x)^3.
The Hosoya-Wiener polynomial is conjectured to be 4nt +(1/2)n(n+9)t^2 + n(n-4)t^3 + (1/2)n(n-7)t^4.
MAPLE
a := proc (n) options operator, arrow: 6*n^2-13*n end proc: seq(a(n), n = 7 .. 45);
MATHEMATICA
DeleteCases[CoefficientList[Series[x^7*(203 - 329 x + 138 x^2)/(1 - x)^3, {x, 0, 45}], x], 0] (* or *)
Array[6 #^2 - 13 # &, 39, 7] (* Michael De Vlieger, May 27 2018 *)
PROG
(PARI) a(n)=6*n^2-13*n \\ Charles R Greathouse IV, Jun 17 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Emeric Deutsch, Aug 27 2013
STATUS
approved