login
A199018
(3*11^n-1)/2.
1
1, 16, 181, 1996, 21961, 241576, 2657341, 29230756, 321538321, 3536921536, 38906136901, 427967505916, 4707642565081, 51784068215896, 569624750374861, 6265872254123476, 68924594795358241, 758170542748940656, 8339875970238347221
OFFSET
0,2
FORMULA
a(n) = 11*a(n-1)+5.
a(n) = 12*a(n-1)-11*a(n-2), n>1.
G.f.: (1 + 4*x)/(1 - 12*x + 11*x^2). - Vincenzo Librandi, Jan 04 2013
MATHEMATICA
(3*11^Range[0, 20]-1)/2 (* or *) LinearRecurrence[{12, -11}, {1, 16}, 20] (* Harvey P. Dale, Jul 16 2012 *)
CoefficientList[Series[(1 + 4*x)/(1 - 12*x + 11*x^2), {x, 0, 30}], x] (* Vincenzo Librandi, Jan 04 2013 *)
PROG
(Magma) [(3*11^n-1)/2 : n in [0..20]]
CROSSREFS
Sequence in context: A218895 A016909 A001455 * A204608 A279282 A231135
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Nov 02 2011
STATUS
approved