A196662 Expansion of g.f. (1-3*x)/(1-10*x).
1, 7, 70, 700, 7000, 70000, 700000, 7000000, 70000000, 700000000, 7000000000, 70000000000, 700000000000, 7000000000000, 70000000000000, 700000000000000, 7000000000000000, 70000000000000000, 700000000000000000, 7000000000000000000, 70000000000000000000
Offset: 0
Links
- Index entries for linear recurrences with constant coefficients, signature (10).
Programs
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Mathematica
CoefficientList[Series[(1-3x)/(1-10x),{x,0,20}],x] (* or *) LinearRecurrence[ {10},{1,7},30] (* or *) Join[{1},NestList[10#&,7,20]] (* Harvey P. Dale, Dec 18 2021 *)
Formula
a(0) = 1, a(n) = 7*10^(n-1) for n>0.
a(n) = Sum_{k=0..n} A193722(n,k)*3^k.
From Elmo R. Oliveira, Mar 18 2025: (Start)
E.g.f.: (7*exp(10*x) + 3)/10.
a(n) = 10*a(n-1). (End)