A084244 a(0)=1, a(1)=5, a(n) = -3*a(n-1), n>1.
1, 5, -15, 45, -135, 405, -1215, 3645, -10935, 32805, -98415, 295245, -885735, 2657205, -7971615, 23914845, -71744535, 215233605, -645700815, 1937102445, -5811307335, 17433922005, -52301766015, 156905298045, -470715894135, 1412147682405, -4236443047215
Offset: 0
Links
- Winston de Greef, Table of n, a(n) for n = 0..2081
- Index entries for linear recurrences with constant coefficients, signature (-3).
Crossrefs
Cf. A083581.
Programs
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Mathematica
Join[{1},NestList[-3#&,5,30]] (* Harvey P. Dale, Jan 29 2013 *)
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PARI
a(n)=8*0^n/3 - 5*(-3)^n/3 \\ Winston de Greef, Mar 19 2023
Formula
a(n) = 8*0^n/3 - 5*(-3)^n/3.
G.f.: (1 + 8*x)/(1 + 3*x).
E.g.f.: (8 - 5*exp(-3*x))/3.
Comments