A248341 a(n) = 10^n - 7^n.
0, 3, 51, 657, 7599, 83193, 882351, 9176457, 94235199, 959646393, 9717524751, 98022673257, 986158712799, 9903110989593, 99321776927151, 995252438490057, 9966767069430399, 99767369486012793, 998371586402089551, 9988601104814626857
Offset: 0
Links
- Index entries for linear recurrences with constant coefficients, signature (17,-70).
Crossrefs
Programs
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Magma
[10^n-7^n: n in [0..30]];
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Mathematica
Table[10^n - 7^n, {n, 0, 25}] (* or *) CoefficientList[Series[3 x/((1 - 7 x) (1 - 10 x)), {x, 0, 30}], x] LinearRecurrence[{17,-70},{0,3},20] (* Harvey P. Dale, Dec 18 2020 *)
Formula
G.f.: 3*x/((1-7*x)*(1-10*x)).
a(n) = 17*a(n-1) - 70*a(n-2).
a(n+1) = 3*A016181(n).
E.g.f.: 2*exp(17*x/2)*sinh(3*x/2). - Elmo R. Oliveira, Apr 01 2025