OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..500
Index entries for linear recurrences with constant coefficients, signature (9, -21, 19, -6).
FORMULA
a(0)=1, a(1)=5, a(2)=32, a(3)=207, a(n)=9*a(n-1)-21*a(n-2)+19*a(n-3)- 6*a(n-4). - Harvey P. Dale, Mar 26 2014
G.f.: (5*x^3+8*x^2-4*x+1)/((x-1)^3*(6*x-1)). - Harvey P. Dale, Mar 26 2014
MATHEMATICA
Table[6^n-n^2, {n, 0, 20}] (* or *) LinearRecurrence[{9, -21, 19, -6}, {1, 5, 32, 207}, 20] (* Harvey P. Dale, Mar 26 2014 *)
PROG
(Magma) [6^n-n^2: n in [0..25]]; // Vincenzo Librandi, Jul 03 2011
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved