A139742 a(n) = 11^n - 4^n.
0, 7, 105, 1267, 14385, 160027, 1767465, 19470787, 214293345, 2357685547, 25936376025, 285307476307, 3138411599505, 34522645035067, 379749565147785, 4177247095673827, 45949725568604865, 505447011319424587, 5559917244772754745, 61159090173536639347, 672749993833048381425
Offset: 0
Links
- Vincenzo Librandi, Table of n, a(n) for n = 0..300
- Index entries for linear recurrences with constant coefficients, signature (15,-44).
Programs
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Magma
[11^n-4^n: n in [0..30]]; // Vincenzo Librandi, Jun 02 2011
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Mathematica
Table[11^n-4^n,{n,0,30}] (* or *) LinearRecurrence[{15,-44},{0,7},30] (* Harvey P. Dale, Dec 10 2013 *)
Formula
a(n) = 15*a(n-1) - 44*a(n-2). - Vincenzo Librandi, Jun 02 2011
From Elmo R. Oliveira, Apr 01 2025: (Start)
G.f.: 7*x/((1-4*x)*(1-11*x)).
E.g.f.: 2*exp(15*x/2)*sinh(7*x/2).
a(n) = 7*A016158(n-1) for n >= 1. (End)