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A261800 Number of 8-compositions of n: matrices with 8 rows of nonnegative integers with positive column sums and total element sum n. 2
1, 8, 100, 1208, 14554, 175352, 2112772, 25456328, 306717703, 3695574048, 44527157584, 536497912672, 6464145163032, 77885061063584, 938419943222768, 11306815168562400, 136233325153964242, 1641445323534504928, 19777413104380161776, 238293693669343744032 (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 an octonary alphabet whose letters appear in alphabetical order.

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..925

Index entries for linear recurrences with constant coefficients, signature (16,-56,112,-140,112,-56,16,-2).

FORMULA

G.f.: (1-x)^8/(2*(1-x)^8-1).

a(n) = A261780(n,8).

MAPLE

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

      add(a(n-j)*binomial(j+7, 7), j=1..n))

    end:

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

CROSSREFS

Column k=8 of A261780.

Sequence in context: A229282 A179485 A144072 * A208705 A246237 A234513

Adjacent sequences:  A261797 A261798 A261799 * A261801 A261802 A261803

KEYWORD

nonn,easy

AUTHOR

Alois P. Heinz, Sep 01 2015

STATUS

approved

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Last modified May 22 13:18 EDT 2017. Contains 286872 sequences.