A165755 a(n) = (5-3*5^n)/2.

1, -5, -35, -185, -935, -4685, -23435, -117185, -585935, -2929685, -14648435, -73242185, -366210935, -1831054685, -9155273435, -45776367185, -228881835935, -1144409179685, -5722045898435, -28610229492185

Offset

0,2

Links

G. C. Greubel, Table of n, a(n) for n = 0..500

Index entries for linear recurrences with constant coefficients, signature (6, -5).

Formula

a(n) = 5*a(n-1) - 10, a(0)=1.

a(n) = 6*a(n-1)-5*a(n-2), a(0)= 1, a(1)= -5, for n>1.

G.f.: (1-11x)/(1-6x+5x^2).

a(n) = Sum_{0<=k<=n} A112555(n,k)*(-6)^(n-k).

a(n) = (-5)*A057651(n-1).

E.g.f.: (1/2)*(5*exp(x) - 3*exp(5*x)). - G. C. Greubel, Apr 07 2016

Mathematica

(5-3*5^Range[0, 20])/2 (* or *) LinearRecurrence[{6, -5}, {1, -5}, 20] (* Harvey P. Dale, Apr 18 2013 *)

Prog

(PARI) x='x+O('x^99); Vec((1-11*x)/(1-6*x+5*x^2)) \\ Altug Alkan, Apr 07 2016

Crossrefs

Sequence in context: A359520 A376496 A043014 * A166149 A002737 A241779

Adjacent sequences: A165752 A165753 A165754 * A165756 A165757 A165758

Keyword

easy,sign

Author

Philippe Deléham, Sep 26 2009

Status

approved