login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A298792 Coordination sequence for the bil tiling (or net) with respect to a trivalent node of the first type. 4
1, 3, 6, 9, 11, 14, 19, 22, 23, 25, 30, 35, 35, 36, 41, 46, 49, 49, 52, 57, 60, 63, 64, 67, 71, 74, 79, 80, 81, 85, 90, 95, 93, 94, 101, 106, 109, 107, 110, 117, 120, 123, 122, 125, 131, 134, 139, 138, 139, 145, 150, 155, 151, 152, 161, 166, 169, 165, 168, 177 (list; graph; refs; listen; history; text; internal format)
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 + 5*x^2 + 7*x^3 + 10*x^4 + 12*x^5 + 15*x^6 + 14*x^7 + 16*x^8 + 14*x^9 + 15*x^10 + 12*x^11 + 10*x^12 + 7*x^13 + 5*x^14 + 2*x^15 + x^16) / ((1 - x)^2*(1 + x^2)*(1 - x + x^2 - x^3 + x^4)*(1 + x + x^2 + x^3 + x^4)^2).
a(n) = a(n-1) - 2*a(n-2) + 2*a(n-3) - 2*a(n-4) + 3*a(n-5) - 3*a(n-6) + 4*a(n-7) - 4*a(n-8) + 4*a(n-9) - 3*a(n-10) + 3*a(n-11) - 2*a(n-12) + 2*a(n-13) - 2*a(n-14) + a(n-15) - a(n-16) for n>16.
(End)
PROG
(PARI) See Links section.
CROSSREFS
Sequence in context: A151926 A166265 A145283 * A177800 A310147 A310148
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jan 27 2018
EXTENSIONS
More terms from Rémy Sigrist, Mar 30 2018
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 25 01:06 EDT 2024. Contains 371964 sequences. (Running on oeis4.)