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A298794
Coordination sequence for the bil tiling (or net) with respect to a trivalent node of the third type.
4
1, 3, 6, 7, 11, 16, 19, 21, 21, 26, 33, 33, 35, 36, 39, 49, 49, 48, 51, 55, 65, 64, 61, 65, 69, 80, 81, 75, 79, 86, 95, 95, 89, 92, 101, 111, 111, 104, 105, 117, 127, 124, 119, 119, 131, 144, 139, 133, 133, 146, 161, 153, 147, 148, 159, 177, 169, 160, 163, 175
OFFSET
0,2
LINKS
Reticular Chemistry Structure Resource (RCSR), The bil tiling (or net)
FORMULA
Conjectures from Colin Barker, Mar 30 2018: (Start)
G.f.: (1 + 2*x + 4*x^2 + 3*x^3 + 9*x^4 + 9*x^5 + 13*x^6 + 9*x^7 + 16*x^8 + 14*x^9 + 18*x^10 + 8*x^11 + 14*x^12 + 9*x^13 + 9*x^14 + 3*x^15 + 5*x^16 + x^17 + 2*x^18 - x^20) / ((1 - x)^2*(1 - x + x^2 - x^3 + x^4)*(1 + x^4)*(1 + x + x^2 + x^3 + x^4)^2).
a(n) = a(n-1) - a(n-2) + a(n-3) - 2*a(n-4) + 3*a(n-5) - 3*a(n-6) + 3*a(n-7) - 3*a(n-8) + 4*a(n-9) - 3*a(n-10) + 3*a(n-11) - 3*a(n-12) + 3*a(n-13) - 2*a(n-14) + a(n-15) - a(n-16) + a(n-17) - a(n-18) for>18.
(End)
PROG
(PARI) See Links section.
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jan 27 2018
EXTENSIONS
More terms from Rémy Sigrist, Mar 30 2018
STATUS
approved