A294327 a(n) = ((9*n + 8)*10^n - 8)/9.
0, 18, 288, 3888, 48888, 588888, 6888888, 78888888, 888888888, 9888888888, 108888888888, 1188888888888, 12888888888888, 138888888888888, 1488888888888888, 15888888888888888, 168888888888888888, 1788888888888888888, 18888888888888888888, 198888888888888888888
Offset: 0
Links
- Colin Barker, Table of n, a(n) for n = 0..900
- Index entries for linear recurrences with constant coefficients, signature (21,-120,100).
Programs
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PARI
concat(0, Vec(18*x*(1 - 5*x) / ((1 - x)*(1 - 10*x)^2) + O(x^30))) \\ Colin Barker, Oct 28 2017
Formula
From Colin Barker, Oct 28 2017: (Start)
G.f.: 18*x*(1 - 5*x) / ((1 - x)*(1 - 10*x)^2).
a(n) = 21*a(n-1) - 120*a(n-2) + 100*a(n-3) for n>2.
(End)