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A261846
Number of compositions of n into distinct parts where each part i is marked with a word of length i over an octonary alphabet whose letters appear in alphabetical order.
2
1, 8, 36, 696, 2250, 14712, 245508, 737352, 3644355, 17376832, 325225824, 823612736, 3820113552, 14264475648, 66782014272, 1254553664640, 2949123559125, 12008271483720, 41150373332932, 157262062899640, 608878151760410, 12804954311547288, 27181470392583156
OFFSET
0,2
COMMENTS
Also matrices with eight rows of nonnegative integers with distinct positive column sums and total element sum n.
LINKS
MAPLE
b:= proc(n, i, p) option remember;
`if`(i*(i+1)/2<n, 0, `if`(n=0, p!, b(n, i-1, p)+
`if`(i>n, 0, b(n-i, i-1, p+1)*binomial(i+7, 7))))
end:
a:= n-> b(n$2, 0):
seq(a(n), n=0..25);
CROSSREFS
Column k=8 of A261835.
Sequence in context: A203020 A276175 A050536 * A110215 A281465 A302619
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Sep 03 2015
STATUS
approved