A298794 Coordination sequence for the bil tiling (or net) with respect to a trivalent node of the third type.

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

Rémy Sigrist, Table of n, a(n) for n = 0..1000

Reticular Chemistry Structure Resource (RCSR), The bil tiling (or net)

Rémy Sigrist, Illustration of first terms

Rémy Sigrist, PARI program for A298794

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

Cf. A298792, A298793, A298795.

Sequence in context: A364927 A258233 A015819 * A181683 A084125 A053478

Adjacent sequences: A298791 A298792 A298793 * A298795 A298796 A298797

Keyword

nonn

Author

N. J. A. Sloane, Jan 27 2018

Extensions

More terms from Rémy Sigrist, Mar 30 2018

Status

approved