OFFSET
0,2
COMMENTS
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.
LINKS
FORMULA
Conjectures from Chai Wah Wu, Jan 12 2023: (Start)
a(n) = - a(n-2) + a(n-3) + a(n-5) - a(n-6) + a(n-7) - a(n-8) + 2*a(n-9) - a(n-10) + a(n-11) - a(n-12) + a(n-13) + a(n-15) - a(n-16) - a(n-18) for n > 18.
G.f.: (x^18 + 5*x^17 + 9*x^16 + 15*x^15 + 23*x^14 + 25*x^13 + 31*x^12 + 30*x^11 + 32*x^10 + 32*x^9 + 32*x^8 + 30*x^7 + 31*x^6 + 25*x^5 + 23*x^4 + 15*x^3 + 9*x^2 + 5*x + 1)/((x - 1)^2*(x^2 + 1)^2*(x^2 + x + 1)*(x^4 - x^2 + 1)*(x^6 + x^5 + x^4 + x^3 + x^2 + x + 1)). (End)
CROSSREFS
KEYWORD
nonn
AUTHOR
Brian Galebach and N. J. A. Sloane, Jun 18 2018
STATUS
approved