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

0,2

Comments

Binomial transform is A083581.

Links

Winston de Greef, Table of n, a(n) for n = 0..2081

Index entries for linear recurrences with constant coefficients, signature (-3).

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.

Mathematica

Join[{1}, NestList[-3#&, 5, 30]] (* Harvey P. Dale, Jan 29 2013 *)

Prog

(PARI) a(n)=8*0^n/3 - 5*(-3)^n/3 \\ Winston de Greef, Mar 19 2023

Crossrefs

Cf. A083581.

Sequence in context: A000335 A271180 A200465 * A005030 A200664 A099235

Adjacent sequences: A084241 A084242 A084243 * A084245 A084246 A084247

Keyword

easy,sign

Author

Paul Barry, May 23 2003

Status

approved