login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A015381 Gaussian binomial coefficient [ n,9 ] for q=-9. 13
1, -348678440, 136773736379522605, -52916360230556551635386480, 20504007291105533368839949866598015, -7943538006665671364765186721016327317109448, 3077495169782617972230910362141435994555138110002155 (list; graph; refs; listen; history; text; internal format)
OFFSET

9,2

REFERENCES

J. Goldman and G.-C. Rota, The number of subspaces of a vector space, pp. 75-83 of W. T. Tutte, editor, Recent Progress in Combinatorics. Academic Press, NY, 1969.

I. P. Goulden and D. M. Jackson, Combinatorial Enumeration. Wiley, NY, 1983, p. 99.

M. Sved, Gaussians and binomials, Ars. Combinatoria, 17A (1984), 325-351.

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 9..120

FORMULA

a(n) = Product_{i=1..9} ((-9)^(n-i+1)-1)/((-9)^i-1). - Vincenzo Librandi, Nov 04 2012

MATHEMATICA

Table[QBinomial[n, 9, -9], {n, 9, 20}] (* Vincenzo Librandi, Nov 04 2012 *)

PROG

(Sage) [gaussian_binomial(n, 9, -9) for n in xrange(9, 15)] # Zerinvary Lajos, May 25 2009

(MAGMA) r:=9; q:=-9; [&*[(1-q^(n-i+1))/(1-q^i): i in [1..r]]: n in [r..20]]; // Vincenzo Librandi, Nov 04 2012

CROSSREFS

Cf. Gaussian binomial coefficients [n, 9] for q = -2..-13: A015371, A015375, A015376, A015377, A015378, A015379, A015380, A015382, A015383, A015384, A015385. - Vincenzo Librandi, Nov 04 2012

Sequence in context: A113739 A159448 A316745 * A257384 A186628 A032757

Adjacent sequences:  A015378 A015379 A015380 * A015382 A015383 A015384

KEYWORD

sign,easy

AUTHOR

Olivier Gérard

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 22 01:06 EDT 2019. Contains 321406 sequences. (Running on oeis4.)