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

 

Logo

"Email this user" was broken Aug 14 to 9am Aug 16. If you sent someone a message in this period, please send it again.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A261801 Number of 9-compositions of n: matrices with 9 rows of nonnegative integers with positive column sums and total element sum n. 2
1, 9, 126, 1704, 22986, 310086, 4183260, 56435004, 761346207, 10271072557, 138563678736, 1869317246556, 25218347263608, 340212470558832, 4589695110222504, 61918074814238448, 835316485437693186, 11268981358631127288, 152026139882340589466 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Also the number of compositions of n where each part i is marked with a word of length i over a nonary alphabet whose letters appear in alphabetical order.

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..880

FORMULA

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

a(n) = A261780(n,9).

MAPLE

a:= proc(n) option remember; `if`(n=0, 1,

      add(a(n-j)*binomial(j+8, 8), j=1..n))

    end:

seq(a(n), n=0..20);

CROSSREFS

Column k=9 of A261780.

Sequence in context: A261743 A229283 A144073 * A065086 A246238 A234573

Adjacent sequences:  A261798 A261799 A261800 * A261802 A261803 A261804

KEYWORD

nonn,easy

AUTHOR

Alois P. Heinz, Sep 01 2015

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified August 17 07:59 EDT 2017. Contains 290635 sequences.