A199412 a(n) = (9*6^n+1)/5.
2, 11, 65, 389, 2333, 13997, 83981, 503885, 3023309, 18139853, 108839117, 653034701, 3918208205, 23509249229, 141055495373, 846332972237, 5077997833421, 30467987000525, 182807922003149, 1096847532018893, 6581085192113357, 39486511152680141
Offset: 0
Links
- Vincenzo Librandi, Table of n, a(n) for n = 0..1000
- Index entries for linear recurrences with constant coefficients, signature (7,-6).
Programs
-
Magma
[(9*6^n+1)/5: n in [0..30]];
Formula
a(n) = 6*a(n-1)-1.
a(n) = 7*a(n-1)-6*a(n-2).
G.f.: (2-3*x)/((1-x)*(1-6*x)).