A244721 - OEIS

%I #5 Jul 06 2014 16:32:57

%S 2,28,210,1158,5112,19206,63494,189092,516528,1310128,3119942,7027866,

%T 15082152,30994832,61292380,117063670,216690678,389814504,683256278,

%U 1169346934,1957831816,3212249500,5172450680,8185057350,12743907242,19544000940,29551096298

%N Number of compositions of n with exactly 9 transitions between different parts.

%H Alois P. Heinz, <a href="/A244721/b244721.txt">Table of n, a(n) for n = 15..900</a>

%p b:= proc(n, v) option remember; `if`(n=0, [1, 0$9],

%p       add(`if`(v in [0, i], b(n-i, `if`(i<=n-i, i, -1)),

%p       [0, b(n-i, `if`(i<=n-i, i, -1))[1..9][]]), i=1..n))

%p     end:

%p a:= n-> b(n, 0)[10]:

%p seq(a(n), n=15..60);

%Y Column k=9 of A238279.

%K nonn

%O 15,1

%A _Joerg Arndt_ and _Alois P. Heinz_, Jul 04 2014