A074580 a(n) = 7^n + 8^n + 9^n.
3, 24, 194, 1584, 13058, 108624, 911234, 7703664, 65588738, 561991824, 4843001474, 41948320944, 364990300418, 3188510652624, 27953062038914, 245823065693424, 2167728096132098, 19161612027339024, 169737447404391554
Offset: 0
Links
- Vincenzo Librandi, Table of n, a(n) for n = 0..300
- Index entries for linear recurrences with constant coefficients, signature (24,-191,504).
Programs
-
Magma
[7^n + 8^n + 9^n: n in [0..20]]; // Vincenzo Librandi, May 20 2011
-
Mathematica
Table[7^n + 8^n + 9^n, {n, 0, 18}] LinearRecurrence[{24,-191,504},{3,24,194},20] (* Harvey P. Dale, Jun 09 2019 *) -
PARI
a(n)=7^n+8^n+9^n \\ Charles R Greathouse IV, Jun 10 2011
Formula
From Mohammad K. Azarian, Dec 26 2008: (Start)
G.f.: 1/(1-7*x) + 1/(1-8*x) + 1/(1-9*x).
E.g.f.: e^(7*x) + e^(8*x) + e^(9*x). (End)