A082541 a(n) = (7*3^n - 4*0^n)/3.
1, 7, 21, 63, 189, 567, 1701, 5103, 15309, 45927, 137781, 413343, 1240029, 3720087, 11160261, 33480783, 100442349, 301327047, 903981141, 2711943423, 8135830269, 24407490807, 73222472421, 219667417263, 659002251789, 1977006755367
Offset: 0
Links
- Vincenzo Librandi, Table of n, a(n) for n = 0..1000
- Index entries for linear recurrences with constant coefficients, signature (3)
Crossrefs
Cf. A083497.
Programs
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Magma
[(7*3^n-4*0^n)/3: n in [0..30]]; // Vincenzo Librandi, Sep 15 2011
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Mathematica
Join[{1},NestList[3#&,7,30]] (* Harvey P. Dale, May 07 2019 *) -
PARI
a(n)=(7*3^n-4*0^n)/3 \\ Charles R Greathouse IV, Oct 07 2015
Formula
G.f.: (1+4*x)/(1-3*x).
E.g.f.: (7*exp(3*x) - 4*exp(0))/3.
a(n) = A005032(n-1), n > 0. - R. J. Mathar, Sep 17 2008
Comments