A074532 a(n) = 2^n + 4^n + 5^n.
3, 11, 45, 197, 897, 4181, 19785, 94637, 456417, 2215781, 10815225, 53024477, 260921937, 1287820181, 6371967465, 31591352717, 156882923457, 780119453381, 3883417004505, 19348364759357, 96466944316977, 481235206811381
Offset: 0
Links
- Vincenzo Librandi, Table of n, a(n) for n = 0..200
- Index entries for linear recurrences with constant coefficients, signature (11,-38,40).
Programs
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Magma
[2^n + 4^n + 5^n: n in [0..25]]; // Vincenzo Librandi, Jun 11 2011
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Mathematica
Table[2^n + 4^n + 5^n, {n, 0, 20}]
Formula
From Mohammad K. Azarian, Dec 27 2008: (Start)
G.f.: 1/(1-2*x) + 1/(1-4*x) + 1/(1-5*x).
E.g.f.: exp(2*x) + exp(4*x) + exp(5*x). (End)