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Number of symmetrically unique Dyck paths of semilength n and height eight.
2

%I #6 Sep 09 2017 11:39:31

%S 1,8,71,461,2706,14235,70161,327469,1469596,6389144,27097948,

%T 112630404,460511702,1857372265,7406424903,29250500171,114576069911,

%U 445647539540,1722814022086,6624828067482,25356181172529,96650473757117,367059233827762,1389476976680608

%N Number of symmetrically unique Dyck paths of semilength n and height eight.

%H Alois P. Heinz, <a href="/A291892/b291892.txt">Table of n, a(n) for n = 8..1000</a>

%H <a href="/index/Rec#order_15">Index entries for linear recurrences with constant coefficients</a>, signature (15, -84, 178, 160, -1436, 1985, 1447, -6220, 4096, 3445, -5665, 1925, 405, -275, 25).

%F G.f.: x^8*(-1+7*x-35*x^2+110*x^3-171*x^4+113*x^5-25*x^6+5*x^7) / ((x-1) *(x^2-3*x+1) *(5*x^2-5*x+1) *(x^3+3*x^2-1) *(x^3-9*x^2+6*x-1) *(5*x^4-5*x^2+1)).

%Y Column k=8 of A291883.

%K nonn,easy

%O 8,2

%A _Alois P. Heinz_, Sep 05 2017