OFFSET
0,1
COMMENTS
Also maximum leaf number of the (n+3)-Apollonian network for n >= 0. - Eric W. Weisstein, Jan 17 2018
LINKS
Eric Weisstein's World of Mathematics, Apollonian Network
Eric Weisstein's World of Mathematics, Maximum Leaf Number
Index entries for linear recurrences with constant coefficients, signature (3).
FORMULA
G.f.: 13/(1-3*x).
a(n) = 3*a(n-1).
a(n) = 13*A000244(n).
E.g.f.: 13*exp(3*x). - Elmo R. Oliveira, Aug 16 2024
MATHEMATICA
Table[13 3^n, {n, 0, 30}]
13 3^Range[0, 20] (* Eric W. Weisstein, Jan 17 2018 *)
LinearRecurrence[{3}, {13}, 20] (* Eric W. Weisstein, Jan 17 2018 *)
CoefficientList[Series[13/(1 - 3 x), {x, 0, 20}], x] (* Eric W. Weisstein, Jan 17 2018 *)
PROG
(Magma) [13*3^n: n in [0..30]];
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Jun 05 2015
STATUS
approved