OFFSET
1,1
LINKS
Robert Israel, Table of n, a(n) for n = 1..3315
J. Nilsson, On Counting the Number of Tilings of a Rectangle with Squares of Size 1 and 2, Journal of Integer Sequences, Vol. 20 (2017), Article 17.2.2. [Page 10, Lemma 5]
Index entries for linear recurrences with constant coefficients, signature (2,2,-3,-2).
FORMULA
G.f.: 2*x*(2*x^2+3*x+2)/((2*x-1)*(x+1)*(x^2+x-1)). - Robert Israel, Aug 29 2017
MAPLE
f:= gfun:-rectoproc({2*a(n)+3*a(n+1)-2*a(n+2)-2*a(n+3)+a(n+4), a(0) = 0, a(1) = 4, a(2) = 14, a(3) = 40}, a(n), remember):
map(f, [$1..100]); # Robert Israel, Aug 29 2017
MATHEMATICA
LinearRecurrence[{2, 2, -3, -2}, {4, 14, 40, 96}, 31] (* Jean-François Alcover, Aug 27 2022 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Eric M. Schmidt, Aug 29 2017
STATUS
approved