A313296 - OEIS

%I #8 May 16 2026 23:36:12

%S 1,4,9,15,21,27,33,39,45,51,56,60,64,69,75,81,87,93,99,105,111,116,

%T 120,124,129,135,141,147,153,159,165,171,176,180,184,189,195,201,207,

%U 213,219,225,231,236,240,244,249,255,261,267

%N Coordination sequence Gal.6.209.1 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_, May 16 2026: (Start)

%F a(n) = a(n-1) + a(n-11) - a(n-12) for n > 12.

%F G.f.: (x + 1)^2*(x^2 + x + 1)*(x^4 - x^3 + x^2 - x + 1)*(x^4 + x^3 + x^2 + x + 1)/(x^12 - x^11 - x + 1). (End)

%K nonn,more

%O 0,2

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