A198698 a(n) = 3*10^n - 1.
2, 29, 299, 2999, 29999, 299999, 2999999, 29999999, 299999999, 2999999999, 29999999999, 299999999999, 2999999999999, 29999999999999, 299999999999999, 2999999999999999, 29999999999999999, 299999999999999999, 2999999999999999999, 29999999999999999999, 299999999999999999999
Offset: 0
Links
- Vincenzo Librandi, Table of n, a(n) for n = 0..200
- Index entries for linear recurrences with constant coefficients, signature (11,-10).
Programs
-
Magma
[3*10^n-1: n in [0..30]];
Formula
a(n) = 10*a(n-1) + 9, a(0)=2.
a(n) = 11*a(n-1) - 10*a(n-2), n>1.
G.f.: (2+7*x)/((10*x-1)*(x-1)). - R. J. Mathar, Oct 30 2011
E.g.f.: exp(x)*(3*exp(9*x) - 1). - Elmo R. Oliveira, Jun 13 2025