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A190987 a(n) = 10*a(n-1) - 5*a(n-2), with a(0)=0, a(1)=1. 3
0, 1, 10, 95, 900, 8525, 80750, 764875, 7245000, 68625625, 650031250, 6157184375, 58321687500, 552430953125, 5232701093750, 49564856171875, 469485056250000, 4447026281640625, 42122837535156250, 398993243943359375, 3779318251757812500, 35798216297861328125 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..21.

Index entries for linear recurrences with constant coefficients, signature (10,-5).

FORMULA

a(n) = (1/20)*sqrt(5)*((5+2*sqrt(5))^n - (5-2*sqrt(5))^n). - Paolo P. Lava, May 31 2011

G.f.: x/(1 - 10*x + 5*x^2). - Philippe Deléham, Oct 12 2011

MATHEMATICA

LinearRecurrence[{10, -5}, {0, 1}, 50]

CROSSREFS

Cf. A190958 (index to generalized Fibonacci sequences).

Cf. A019934 (sqrt(5-2*sqrt(5))), A019952 (sqrt(5+2*sqrt(5))).

Sequence in context: A287830 A259289 A163738 * A233738 A277441 A307021

Adjacent sequences:  A190984 A190985 A190986 * A190988 A190989 A190990

KEYWORD

nonn,easy

AUTHOR

Vladimir Joseph Stephan Orlovsky, May 24 2011

STATUS

approved

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Last modified July 6 11:37 EDT 2022. Contains 355110 sequences. (Running on oeis4.)