OFFSET
0,3
COMMENTS
A floretion-generated sequence of squares.
This sequence is also related to several other sequences of squares.
LINKS
Harvey P. Dale, Table of n, a(n) for n = 0..1000
Creighton Dement, Online Floretion Multiplier. [broken link]
Index entries for linear recurrences with constant coefficients, signature (-2,6,27).
FORMULA
a(n+3) = -2a(n+2) + 6a(n+1) + 27a(n), a(0) = 1, a(1) = 1, a(2) = 4.
a(n) = (1/11)*(2*3^n-(-5/2-(I*sqrt(11))/2)^n-(-5/2+(I*sqrt(11))/2)^n). [Creighton Dement, May 24 2009]
11*a(n) = 6*3^n + 5*b(n) + 18*b(n-1) where b(n) = (-1)^n*A190970(n+1). - R. J. Mathar, Mar 23 2023
MAPLE
MATHEMATICA
CoefficientList[Series[(3x+1)/(1+2x-6x^2-27x^3), {x, 0, 30}], x] (* or *) LinearRecurrence[{-2, 6, 27}, {1, 1, 4}, 30] (* Harvey P. Dale, Dec 13 2017 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Creighton Dement, Feb 11 2005
EXTENSIONS
Corrected by T. D. Noe, Nov 07 2006
STATUS
approved