OFFSET
0,1
COMMENTS
From Reeva Bohra and Greg Dresden, Aug 17 2021: (Start)
For n > 0, a(n) is the number of ways to tile, with squares and dominoes, a strip of length n+1 that begins with two vertical strips of heights 3 and 2. As an example, a(5) is the number of ways to tile this figure (of length 6) with squares and dominoes.
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(End)
LINKS
Michael De Vlieger, Table of n, a(n) for n = 0..4781
Tanya Khovanova, Recursive Sequences
Index entries for linear recurrences with constant coefficients, signature (1,1).
FORMULA
G.f.: (4+6x)/(1-x-x^2). - Philippe Deléham, Nov 19 2008
a(n) = 2*A001060(n). - R. J. Mathar, Mar 11 2011
a(n) = Fibonacci(n+5) + Lucas(n-1). - Greg Dresden, Feb 18 2022
a(n) = a(n-1) + a(n-2). - Wesley Ivan Hurt, Mar 08 2022
MATHEMATICA
LinearRecurrence[{1, 1}, {4, 10}, 50] (* Greg Dresden, Aug 17 2021 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved