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A169796 Expansion of ((1-x)/(1-2x))^9. 2
1, 9, 54, 264, 1134, 4446, 16272, 56412, 187137, 598417, 1854882, 5597172, 16498632, 47638512, 135048672, 376592064, 1034663040, 2804590080, 7509232640, 19880294400, 52088352768, 135173578752, 347680161792, 886900948992, 2245014454272, 5641949085696 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

a(n)= number of weak compositions of n with exactly 8 parts are equal 0. [Milan Janjic, Jun 27 2010]

LINKS

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

Nickolas Hein, Jia Huang, Nonassociativity measurements of some binary operations, arXiv:1807.04623 [math.CO], 2018.

M. Janjic and B. Petkovic, A Counting Function, arXiv 1301.4550 [math.CO], 2013.

M. Janjic, B. Petkovic, A Counting Function Generalizing Binomial Coefficients and Some Other Classes of Integers, J. Int. Seq. 17 (2014) # 14.3.5.

FORMULA

G.f.: ((1-x)/(1-2*x))^9.

For n>0, a(n) = 2^(n-16)*(n+8)*(n^7+100*n^6+3778*n^5+68056*n^4+606961*n^3+2543284*n^2+4524300*n+2575440)/315. - Bruno Berselli, Aug 07 2011

CROSSREFS

Cf. for ((1-x)/(1-2x))^k: A011782, A045623, A058396, A062109, A169792-A169797; a row of A160232.

Sequence in context: A282920 A023008 A079817 * A027472 A022637 A001392

Adjacent sequences:  A169793 A169794 A169795 * A169797 A169798 A169799

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane, May 15 2010

STATUS

approved

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Last modified October 15 19:24 EDT 2018. Contains 316237 sequences. (Running on oeis4.)