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A189746 a(1)=5,  a(2)=2, a(n)=5*a(n-1) + 2*a(n-2) 12
5, 2, 20, 104, 560, 3008, 16160, 86816, 466400, 2505632, 13460960, 72316064, 388502240, 2087143328, 11212721120, 60237892256, 323614903520, 1738550302112, 9339981317600, 50177007192224, 269564998596320, 1448179007366048, 7780025034022880, 41796483184846496 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..100

Index entries for linear recurrences with constant coefficients, signature (5, 2).

FORMULA

a(n) = 5/2*((5/2-1/2*sqrt(33))^(n-1)+(5/2+1/2*sqrt(33))^(n-1))+7/22*sqrt(33)*((5/2-1/2*sqrt(33))^(n-1)-(5/2+1/2*sqrt(33))^(n-1)). - Paolo P. Lava, May 24 2011

G.f.: x*(5-23*x)/(1-5*x-2*x^2). - Bruno Berselli, May 24 2011

MATHEMATICA

LinearRecurrence[{5, 2}, {5, 2}, 40]

PROG

(Maxima) a[1]:5$ a[2]:2$ a[n]:=5*a[n-1]+2*a[n-2]$ makelist(a[n], n, 1, 24);  [Bruno Berselli, May 24 2011]

CROSSREFS

Cf. A000045, A000079, A105476, A159612, A080040, A135522, A103435, A189732, A189734, A189735, A189736, A189737, A189738, A189739, A189741, A189742, A189743, A189744, A189745, A189747, A189748, A189749.

Sequence in context: A306198 A276533 A303685 * A191667 A130329 A096035

Adjacent sequences:  A189743 A189744 A189745 * A189747 A189748 A189749

KEYWORD

nonn

AUTHOR

Harvey P. Dale, Apr 26 2011

STATUS

approved

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Last modified September 20 05:51 EDT 2019. Contains 327212 sequences. (Running on oeis4.)