A086944 a(n) = k where R(k+8) = 5.
42, 492, 4992, 49992, 499992, 4999992, 49999992, 499999992, 4999999992, 49999999992, 499999999992, 4999999999992, 49999999999992, 499999999999992, 4999999999999992, 49999999999999992, 499999999999999992, 4999999999999999992, 49999999999999999992, 499999999999999999992
Offset: 1
Links
- Vincenzo Librandi, Table of n, a(n) for n = 1..300
- Index entries for linear recurrences with constant coefficients, signature (11,-10).
Programs
-
Magma
[5*10^n-8: n in [1..25] ]; // Vincenzo Librandi, Aug 22 2011
Formula
a(n) = 5*10^n - 8.
R(a(n)) = A086941(n).
From Elmo R. Oliveira, Apr 30 2025: (Start)
G.f.: 6*x*(5*x+7)/((x-1)*(10*x-1)).
E.g.f.: 3 - 8*exp(x) + 5*exp(10*x).
a(n) = 11*a(n-1) - 10*a(n-2) for n > 2. (End)