OFFSET
0,2
COMMENTS
The sequences in Prop. 5.1 and 5.2 should also be added to the OEIS.
LINKS
Colin Barker, Table of n, a(n) for n = 0..1000
Tomislav Doslic, I. Zubac, Counting maximal matchings in linear polymers, Ars Mathematica Contemporanea 11 (2016) 255-276. See Cor. 4.3.
Index entries for linear recurrences with constant coefficients, signature (2,0,1).
FORMULA
G.f.: (1 + x - x^2) / (1 - 2*x - x^3). - Colin Barker, Apr 23 2017
MAPLE
a:=proc(n) option remember;
if n=0 then 1
elif n=1 then 3
elif n=2 then 5
else 2*a(n-1)+a(n-3); fi;
end;
[seq(a(n), n=0..40)];
MATHEMATICA
LinearRecurrence[{2, 0, 1}, {1, 3, 5}, 40] (* Harvey P. Dale, May 26 2023 *)
PROG
(PARI) Vec((1 + x - x^2) / (1 - 2*x - x^3) + O(x^40)) \\ Colin Barker, Apr 23 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Apr 23 2017
STATUS
approved