A291675 a(n) = a(n-1) + 2*a(n-2) + 8*Fibonacci(n) + 2*Fibonacci(n-1); a(1) = 4, a(2) = 14.

4, 14, 40, 96, 222, 488, 1052, 2222, 4640, 9592, 19694, 40208, 81748, 165646, 334776, 675184, 1359486, 2733720, 5491308, 11021230, 22104944, 44310984, 88785550, 177835776, 356099812, 712892558, 1426906312, 2855626752, 5714188830, 11433127112, 22873939004

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

Sequence in context: A187594 A326482 A331758 * A066375 A093160 A001938

Adjacent sequences: A291672 A291673 A291674 * A291676 A291677 A291678

Keyword

nonn

Author

Eric M. Schmidt, Aug 29 2017

Status

approved