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A244721 Number of compositions of n with exactly 9 transitions between different parts.

%I A244721 #5 Jul 06 2014 16:32:57
%S A244721 2,28,210,1158,5112,19206,63494,189092,516528,1310128,3119942,7027866,
%T A244721 15082152,30994832,61292380,117063670,216690678,389814504,683256278,
%U A244721 1169346934,1957831816,3212249500,5172450680,8185057350,12743907242,19544000940,29551096298
%N A244721 Number of compositions of n with exactly 9 transitions between different parts.
%H A244721 Alois P. Heinz, <a href="/A244721/b244721.txt">Table of n, a(n) for n = 15..900</a>
%p A244721 b:= proc(n, v) option remember; `if`(n=0, [1, 0$9],
%p A244721       add(`if`(v in [0, i], b(n-i, `if`(i<=n-i, i, -1)),
%p A244721       [0, b(n-i, `if`(i<=n-i, i, -1))[1..9][]]), i=1..n))
%p A244721     end:
%p A244721 a:= n-> b(n, 0)[10]:
%p A244721 seq(a(n), n=15..60);
%Y A244721 Column k=9 of A238279.
%K A244721 nonn
%O A244721 15,1
%A A244721 _Joerg Arndt_ and _Alois P. Heinz_, Jul 04 2014