A246059 a(n) = (17*10^n - 8)/9.
1, 18, 188, 1888, 18888, 188888, 1888888, 18888888, 188888888, 1888888888, 18888888888, 188888888888, 1888888888888, 18888888888888, 188888888888888, 1888888888888888, 18888888888888888, 188888888888888888, 1888888888888888888, 18888888888888888888, 188888888888888888888
Offset: 0
Links
- Vincenzo Librandi, Table of n, a(n) for n = 0..100
- Index entries for linear recurrences with constant coefficients, signature (11,-10).
Crossrefs
Cf. similar sequences listed in A246057.
Programs
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Magma
[(17*10^n-8)/9: n in [0..20]];
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Mathematica
Table[(17 10^n - 8)/9, {n, 0, 20}]
Formula
G.f.: (1 + 7*x)/((1 - x)*(1 - 10*x)).
a(n) = 11*a(n-1) - 10*a(n-2).
E.g.f.: exp(x)*(17*exp(9*x) - 8)/9. - Elmo R. Oliveira, May 06 2025