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A244721
Number of compositions of n with exactly 9 transitions between different parts.
2
2, 28, 210, 1158, 5112, 19206, 63494, 189092, 516528, 1310128, 3119942, 7027866, 15082152, 30994832, 61292380, 117063670, 216690678, 389814504, 683256278, 1169346934, 1957831816, 3212249500, 5172450680, 8185057350, 12743907242, 19544000940, 29551096298
OFFSET
15,1
LINKS
MAPLE
b:= proc(n, v) option remember; `if`(n=0, [1, 0$9],
add(`if`(v in [0, i], b(n-i, `if`(i<=n-i, i, -1)),
[0, b(n-i, `if`(i<=n-i, i, -1))[1..9][]]), i=1..n))
end:
a:= n-> b(n, 0)[10]:
seq(a(n), n=15..60);
CROSSREFS
Column k=9 of A238279.
Sequence in context: A123787 A035601 A281124 * A001759 A243475 A019441
KEYWORD
nonn
AUTHOR
Joerg Arndt and Alois P. Heinz, Jul 04 2014
STATUS
approved