|
|
A261843
|
|
Number of compositions of n into distinct parts where each part i is marked with a word of length i over a quinary alphabet whose letters appear in alphabetical order.
|
|
2
|
|
|
1, 5, 15, 185, 420, 1876, 19320, 42610, 149115, 495205, 5516001, 10570145, 35897010, 97383790, 320607680, 3412039628, 6292069835, 19106603405, 49239854095, 138462457915, 378598491878, 4312038483490, 7316190877970, 21527078513430, 50933081112485
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,2
|
|
COMMENTS
|
Also matrices with five 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+4, 4))))
end:
a:= n-> b(n$2, 0):
seq(a(n), n=0..30);
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|