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Central terms of triangle A120894 (cascadence of 1+x+x^2).
3

%I #3 Mar 30 2012 18:36:58

%S 1,1,2,5,10,27,73,189,518,1413,3857,10707,29804,83365,234665,662654,

%T 1878059,5341302,15231940,43552610,124829236,358537455,1031835260,

%U 2974872009,8590929683,24847042484,71964879243,208704926659

%N Central terms of triangle A120894 (cascadence of 1+x+x^2).

%Y Cf. A120894, A120895, A120897.

%K nonn

%O 0,3

%A _Paul D. Hanna_, Jul 14 2006