OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
Index entries for linear recurrences with constant coefficients, signature (10,-25).
FORMULA
G.f.: 5*x/(1 - 5*x)^2. - Vincenzo Librandi, Sep 09 2014
From Amiram Eldar, Jul 20 2020: (Start)
Sum_{n>=1} 1/a(n) = log(5/4).
Sum_{n>=1} (-1)^(n+1)/a(n) = log(6/5). (End)
From Elmo R. Oliveira, Sep 09 2024: (Start)
E.g.f.: 5*x*exp(5*x).
a(n) = 10*a(n-1) - 25*a(n-2) for n > 1. (End)
MAPLE
g:=1/(1-5*z): gser:=series(g, z=0, 43): seq(coeff(gser, z, n)*n, n=0..31); # Zerinvary Lajos, Jan 09 2009
MATHEMATICA
Table[n 5^n, {n, 0, 20}] (* Vincenzo Librandi, Sep 09 2014 *)
PROG
(Magma) [n*5^n: n in [0..20]]; // Vincenzo Librandi, Sep 09 2014
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved