A310704 - OEIS

%I #6 Oct 21 2023 15:10:34

%S 1,4,7,10,15,19,21,24,30,34,35,38,45,49,49,52,60,64,63,66,75,79,77,80,

%T 90,94,91,94,105,109,105,108,120,124,119,122,135,139,133,136,150,154,

%U 147,150,165,169,161,164,180,184

%N Coordination sequence Gal.3.2.2 where Gal.u.t.v denotes the coordination sequence for a vertex of type v in tiling number t in the Galebach list of u-uniform tilings.

%C Note that there may be other vertices in the Galebach list of u-uniform tilings with u <= 6 that have this same coordination sequence. See the Galebach link for the complete list of A-numbers for all these tilings.

%H Brian Galebach, <a href="/A250120/a250120.html">k-uniform tilings (k <= 6) and their A-numbers</a>

%F Conjectures from _Chai Wah Wu_, Dec 24 2019: (Start)

%F a(n) = a(n-1) - a(n-2) + a(n-3) + a(n-4) - a(n-5) + a(n-6) - a(n-7) for n > 7.

%F G.f.: (x^7 + 3*x^6 + 4*x^5 + 7*x^4 + 6*x^3 + 4*x^2 + 3*x + 1)/((x - 1)^2*(x + 1)*(x^2 + 1)^2). (End)

%K nonn

%O 0,2

%A _Brian Galebach_ and _N. J. A. Sloane_, Jun 18 2018