A199684 a(n) = 4*10^n+1.
5, 41, 401, 4001, 40001, 400001, 4000001, 40000001, 400000001, 4000000001, 40000000001, 400000000001, 4000000000001, 40000000000001, 400000000000001, 4000000000000001, 40000000000000001, 400000000000000001, 4000000000000000001
Offset: 0
Links
- Vincenzo Librandi, Table of n, a(n) for n = 0..1000
- Index entries for linear recurrences with constant coefficients, signature (11,-10).
Programs
-
Magma
[4*10^n+1: n in [0..30]];
Formula
a(n) = 10*a(n-1)-9.
a(n) = 11*a(n-1)-10*a(n-2).
G.f.: (5-14*x)/((1-x)*(1-10*x)).
E.g.f.: exp(x) + 4*exp(10*x). - Stefano Spezia, Oct 20 2022