login
A199212
a(n) = 2*5^n+1.
1
3, 11, 51, 251, 1251, 6251, 31251, 156251, 781251, 3906251, 19531251, 97656251, 488281251, 2441406251, 12207031251, 61035156251, 305175781251, 1525878906251, 7629394531251, 38146972656251, 190734863281251, 953674316406251
OFFSET
0,1
FORMULA
a(n) = 5*a(n-1)-4.
a(n) = 6*a(n-1)-5*a(n-2).
G.f.: (3-7*x)/((1-x)*(1-5*x)). - Bruno Berselli, Nov 04 2011
MATHEMATICA
2*5^Range[0, 30]+1 (* or *) LinearRecurrence[{6, -5}, {3, 11}, 30] (* Harvey P. Dale, Aug 26 2024 *)
PROG
(Magma) [2*5^n+1: n in [0..30]];
CROSSREFS
Sequence in context: A284702 A191341 A359146 * A113283 A326519 A127784
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Nov 04 2011
STATUS
approved