OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (14,-49).
FORMULA
From Harvey P. Dale, Aug 08 2011: (Start)
a(n) = 14*a(n-1) - 49*a(n-2) with a(0)=0 and a(1)=7.
G.f.: (7*x)/(7*x-1)^2. (End)
From Amiram Eldar, Jul 20 2020: (Start)
Sum_{n>=1} 1/a(n) = log(7/6).
Sum_{n>=1} (-1)^(n+1)/a(n) = log(8/7). (End)
From Elmo R. Oliveira, Sep 09 2024: (Start)
E.g.f.: 7*x*exp(7*x).
a(n) = n*A000420(n). (End)
MATHEMATICA
Table[n 7^n, {n, 0, 30}] (* or *) LinearRecurrence[{14, -49}, {0, 7}, 31] (* Harvey P. Dale, Aug 08 2011 *)
PROG
(Magma) [n*7^n: n in [0..20]] ; // Vincenzo Librandi, Aug 09 2011
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved