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A033544 Wiener number of n-hexagonal triangle. 4
0, 27, 210, 822, 2328, 5433, 11130, 20748, 36000, 59031, 92466, 139458, 203736, 289653, 402234, 547224, 731136, 961299, 1245906, 1594062, 2015832, 2522289, 3125562, 3838884, 4676640, 5654415, 6789042, 8098650, 9602712, 11322093, 13279098 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

REFERENCES

W. C. Shiu, Wiener numbers ..., Graph Theory Notes of New York 32 (1997), 10-15.

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (6,-15,20,-15,6,-1).

FORMULA

a(n) = (1/10)*n*(n+1)*(4*n^3+36*n^2+79*n+16).

G.f.: 3*x*(2*x^3-11*x^2+16*x+9)/(x-1)^6. [Colin Barker, Oct 30 2012]

MATHEMATICA

CoefficientList[Series[3 x (2 x^3 - 11 x^2 + 16 x + 9)/(x - 1)^6, {x, 0, 30}], x] (* Vincenzo Librandi, Oct 20 2013 *)

PROG

(MAGMA) [(1/10)*n*(n+1)*(4*n^3+36*n^2+79*n+16): n in [0..30]]; // Vincenzo Librandi, Oct 20 2013

CROSSREFS

Sequence in context: A216110 A216112 A183596 * A224874 A125111 A016767

Adjacent sequences:  A033541 A033542 A033543 * A033545 A033546 A033547

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Vincenzo Librandi, Oct 20 2013

STATUS

approved

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Last modified December 16 04:05 EST 2019. Contains 330013 sequences. (Running on oeis4.)