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%I #8 Sep 13 2017 02:13:33
%S 0,0,0,1,1,4,6,13,23,42,68,119,197,324,530,823,1305,2040,3162,4869,
%T 7431,11076,16680,24831,36785,54210,79546,115967,167359,241726,347184,
%U 496235,707681,1004534,1421178,2003969,2806921,3929770,5479406,7617149,10562169
%N Number of compositions of n such that the maximal distance between two identical parts equals two.
%e a(3) = 1: 111.
%e a(4) = 1: 121.
%e a(5) = 4: 131, 212, 1112, 2111.
%e a(6) = 6: 141, 222, 1113, 1212, 2121, 3111.
%e a(7) = 13: 151, 232, 313, 1114, 1213, 1222, 1312, 2131, 2221, 3121, 4111, 11122, 22111.
%e a(8) = 23: 161, 242, 323, 1115, 1214, 1232, 1313, 1412, 2123, 2141, 2321, 3131, 3212, 4121, 5111, 11123, 11132, 11222, 21113, 22211, 23111, 31112, 32111.
%Y Column k=2 of A262191.
%K nonn
%O 0,6
%A _Alois P. Heinz_, Sep 14 2015
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