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A189749 a(1)=5,  a(2)=5, a(n)=5*a(n-1) + 5*a(n-2). 13
5, 5, 50, 275, 1625, 9500, 55625, 325625, 1906250, 11159375, 65328125, 382437500, 2238828125, 13106328125, 76725781250, 449160546875, 2629431640625, 15392960937500, 90111962890625, 527524619140625, 3088182910156250, 18078537646484375, 105833602783203125 (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, 5).

FORMULA

a(n) = 5/2*((5/2+3/2 *sqrt(5))^(n-1)+(5/2-3/2*sqrt(5))^(n-1))+1/2*sqrt(5)*((5/2-3/2*sqrt(5))^(n-1)-(5/2+3/2*sqrt(5))^(n-1)). - Paolo P. Lava, May 24 2011

G.f.: 5*x*(1-4*x)/(1-5*x-5*x^2). - Bruno Berselli, May 24 2011

MATHEMATICA

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

PROG

(Maxima) a[1]:5$ a[2]:5$ a[n]:=5*a[n-1]+5*a[n-2]$ makelist(a[n], n, 1, 23);  [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, A189746, A189747, A189748.

Sequence in context: A065238 A196388 A073128 * A009390 A009334 A151467

Adjacent sequences:  A189746 A189747 A189748 * A189750 A189751 A189752

KEYWORD

nonn

AUTHOR

Harvey P. Dale, Apr 26 2011

STATUS

approved

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Last modified March 30 20:18 EDT 2017. Contains 284302 sequences.