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 A293996 Number of linear chord diagrams having n chords and no chord length larger than four. 2

%I

%S 1,1,3,15,105,315,1141,4779,21101,80559,314185,1267551,5160933,

%T 20504123,81554685,326682775,1310978305,5239019143,20931551661,

%U 83743554723,335175239813,1340542340399,5360923216953,21444223178271,85786427569333,343141430067947

%N Number of linear chord diagrams having n chords and no chord length larger than four.

%H Alois P. Heinz, <a href="/A293996/b293996.txt">Table of n, a(n) for n = 0..1000</a>

%H <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (2,2,11,60,-18,-26,-108,-48)

%F G.f.: -(2*x^4+4*x^3+x^2+x-1) / ((4*x-1) * (12*x^7+30*x^6+14*x^5+8*x^4-13*x^3 -6*x^2 -2*x-1)).

%Y Column k=4 of A293960.

%K nonn,easy

%O 0,3

%A _Alois P. Heinz_, Oct 21 2017

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Last modified August 2 08:47 EDT 2021. Contains 346422 sequences. (Running on oeis4.)