OFFSET
0,2
LINKS
Andrew Howroyd, Table of n, a(n) for n = 0..200
R. Euler, P. Oleksik, Z. Skupien, Counting Maximal Distance-Independent Sets in Grid Graphs, Discussiones Mathematicae Graph Theory. Volume 33, Issue 3, Pages 531-557, ISSN (Print) 2083-5892, July 2013; see also.
Index entries for linear recurrences with constant coefficients, signature (1,0,3,1,0,1,-2,0,-1).
FORMULA
Euler et al. give an explicit g.f. and recurrence.
G.f.: x*(3 + x + 7*x^2 - 3*x^3 + 4*x^4 - 4*x^5 - x^6 - 2*x^7 - x^8) / ((1 + x)*(1 - 2*x + 2*x^2 - 5*x^3 + 4*x^4 - 4*x^5 + 3*x^6 - x^7 + x^8)). - Colin Barker, Oct 03 2017
MATHEMATICA
LinearRecurrence[{1, 0, 3, 1, 0, 1, -2, 0, -1}, {0, 3, 4, 11, 17, 36, 69, 133, 254, 499}, 40] (* Harvey P. Dale, Oct 05 2017 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Nov 17 2013
EXTENSIONS
Terms a(10) and beyond from Andrew Howroyd, Jun 10 2017
STATUS
approved