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A168202 a(n) = 3*n - a(n-1) + 1 with n>1, a(1)=5. 1
5, 2, 8, 5, 11, 8, 14, 11, 17, 14, 20, 17, 23, 20, 26, 23, 29, 26, 32, 29, 35, 32, 38, 35, 41, 38, 44, 41, 47, 44, 50, 47, 53, 50, 56, 53, 59, 56, 62, 59, 65, 62, 68, 65, 71, 68, 74, 71, 77, 74, 80, 77, 83, 80, 86, 83, 89, 86, 92, 89, 95, 92, 98, 95, 101, 98, 104, 101, 107, 104 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Index entries for linear recurrences with constant coefficients, signature (1,1,-1).

FORMULA

From R. J. Mathar, Nov 22 2009: (Start)

a(n) = a(n-1) +a(n-2) -a(n-3).

a(n) = (5 - 9*(-1)^n)/4 + 3*n/2.

G.f.: x*(5 - 3*x + x^2)/((1+x)*(x-1)^2). (End)

E.g.f.: (1/4)*(-9 + 4*exp(x) + (5 + 6*x)*exp(2*x))*exp(-x). - G. C. Greubel, Jul 15 2016

MATHEMATICA

LinearRecurrence[{1, 1, -1}, {5, 2, 8}, 60] (* Vincenzo Librandi, Feb 28 2012 *)

PROG

(MAGMA) I:=[5, 2, 8]; [n le 3 select I[n] else Self(n-1)+Self(n-2)-Self(n-3): n in [1..40]]; // Vincenzo Librandi, Feb 28 2012

CROSSREFS

Sequence in context: A152956 A099873 A185353 * A153455 A193019 A200135

Adjacent sequences:  A168199 A168200 A168201 * A168203 A168204 A168205

KEYWORD

nonn,easy

AUTHOR

Vincenzo Librandi, Nov 20 2009

STATUS

approved

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Last modified November 19 16:10 EST 2017. Contains 294936 sequences.