The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A298786 Expansion of (x^4 + 2*x^3 + 4*x^2 + 2*x + 1) / ((1 - x)*(1 - x^3)). 3
 1, 3, 7, 10, 13, 17, 20, 23, 27, 30, 33, 37, 40, 43, 47, 50, 53, 57, 60, 63, 67, 70, 73, 77, 80, 83, 87, 90, 93, 97, 100, 103, 107, 110, 113, 117, 120, 123, 127, 130, 133, 137, 140, 143, 147, 150, 153, 157, 160, 163, 167, 170, 173, 177, 180, 183, 187, 190, 193, 197, 200, 203, 207, 210, 213, 217 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Appears to be the coordination sequence for a trivalent node in the bex tiling (or net). LINKS Colin Barker, Table of n, a(n) for n = 0..1000 Reticular Chemistry Structure Resource (RCSR), The bex tiling (or net) Index entries for linear recurrences with constant coefficients, signature (1,0,1,-1). FORMULA a(n) = a(n-1) + a(n-3) - a(n-4) for n>4. - Colin Barker, Jan 27 2018 MAPLE f3:=proc(n) if n=0 then 1               elif (n mod 3) = 0 then 10*n/3               elif (n mod 3) = 1 then (10*n-1)/3               else (10*n+1)/3; fi; end; [seq(f3(n), n=0..80)]; PROG (PARI) Vec((1 + 2*x + 4*x^2 + 2*x^3 + x^4) / ((1 - x)^2*(1 + x + x^2)) + O(x^100)) \\ Colin Barker, Jan 27 2018 CROSSREFS Cf. A298784, A298787. Sequence in context: A160591 A297466 A198267 * A285359 A255607 A310185 Adjacent sequences:  A298783 A298784 A298785 * A298787 A298788 A298789 KEYWORD nonn,easy AUTHOR N. J. A. Sloane, Jan 26 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 | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 1 01:37 EST 2021. Contains 349426 sequences. (Running on oeis4.)