OFFSET
0,2
LINKS
Colin Barker, Table of n, a(n) for n = 0..1000
T. Doslic, T. Short, Maximal matchings in polyspiro and benzenoid chains, arXiv:1511.00590, [math.CO], 2015. See Th. 3.4.
Index entries for linear recurrences with constant coefficients, signature (4,4,1).
FORMULA
a(n) = 4*a(n-1)+4*a(n-2)+a(n-3). - Colin Barker, Aug 26 2016
PROG
(PARI) Vec((1+x+x^2)/(1-4*x-4*x^2-x^3) + O(x^40)) \\ Colin Barker, Aug 26 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Aug 25 2016
STATUS
approved