OFFSET
0,3
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
M. Albert, R. Aldred, M. Atkinson, C Handley, D. Holton, D. McCaughan and H. van Ditmarsch, Sorting Classes, Elec. J. of Comb., Vol. 12 (2005), R31.
Index entries for linear recurrences with constant coefficients, signature (2).
FORMULA
a(n) = 3*2^(n-2), n>=3.
a(n) = 2*a(n-1) for n=3. G.f.: (1-x+2*x^3)/(1-2*x). - Colin Barker, Nov 29 2012
MATHEMATICA
Table[If[n == 1, 1, If[n == 2, 2, 3*2^(n - 2)]], {n, 32}] (* Robert G. Wilson v *)
LinearRecurrence[{2}, {1, 2, 6}, 40] (* Harvey P. Dale, Jul 14 2019 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Len Smiley, Nov 01 2005
EXTENSIONS
a(0)=1 prepended by Alois P. Heinz, Mar 12 2024
STATUS
approved