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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A022238 Gaussian binomial coefficients [ n,9 ] for q = 7. 1
1, 47079208, 1939395353553757, 78490432990886231801200, 3168691824510592423395247884703, 127875753071992714335358328311551866824, 5160291746051272234978893428859106387360586971, 208236637980093164825596972398144064919402131047044800 (list; graph; refs; listen; history; text; internal format)
OFFSET

9,2

REFERENCES

F. J. MacWilliams and N. J. A. Sloane, The Theory of Error-Correcting Codes, Elsevier-North Holland, 1978, p. 698.

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 9..140

FORMULA

G.f.: x^9/((1-x)*(1-7*x)*(1-49*x)*(1-343*x)*(1-2401*x)*(1-16807*x)*(1-117649*x)*(1-823543*x)*(1-5764801*x)*(1-40353607*x)). - Vincenzo Librandi, Aug 12 2016

a(n) = Product_{i=1..9} (7^(n-i+1)-1)/(7^i-1), by definition. - Vincenzo Librandi, Aug 12 2016

MATHEMATICA

Table[QBinomial[n, 9, 7], {n, 9, 20}] (* Vincenzo Librandi, Aug 12 2016 *)

PROG

(Sage) [gaussian_binomial(n, 9, 7) for n in xrange(9, 17)] # Zerinvary Lajos, May 25 2009

(MAGMA) r:=9; q:=7; [&*[(1-q^(n-i+1))/(1-q^i): i in [1..r]]: n in [r..20]]; // Vincenzo Librandi, Aug 12 2016

CROSSREFS

Sequence in context: A250598 A237897 A230756 * A121491 A300568 A210334

Adjacent sequences:  A022235 A022236 A022237 * A022239 A022240 A022241

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

EXTENSIONS

Offset changed by Vincenzo Librandi, Aug 12 2016

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 17:25 EDT 2019. Contains 321422 sequences. (Running on oeis4.)