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Number of minimal edge cuts in the 4 X n grid graph.
0

%I #6 Dec 11 2024 17:57:15

%S 3,28,146,627,2471,9292,33878,120771,423251,1463908,5011690,17021179,

%T 57450167,192966908,645696454,2154226075,7170606795,23825657596,

%U 79055534746,262031761435,867792229799,2872103661988,9501035284286,31417942222787,103862506390523,343276150243020

%N Number of minimal edge cuts in the 4 X n grid graph.

%H Andrew Howroyd, <a href="/A378934/b378934.txt">Table of n, a(n) for n = 1..200</a>

%H <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (10,-37,59,-27,-25,21,5,-4,-1).

%F G.f.: x*(3 - 2*x - 23*x^2 + 26*x^3 + 32*x^4 - 2*x^5 - 29*x^6 - 18*x^7 - 3*x^8)/((1 - x)^3*(1 - 2*x - x^2)^2*(1 - 3*x - x^2)).

%F a(n) = 10*a(n-1) - 37*a(n-2) + 59*a(n-3) - 27*a(n-4) - 25*a(n-5) + 21*a(n-6) + 5*a(n-7) - 4*a(n-8) - a(n-9) for n >= 10.

%F a(n) = A166766(n)/2.

%Y Row 4 of A378932.

%Y Cf. A166766, A378933.

%K nonn,new

%O 1,1

%A _Andrew Howroyd_, Dec 11 2024