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A153388 Second bisection of A153382. 1
8, 18, 48, 128, 338, 888, 2328, 6098, 15968, 41808, 109458, 286568, 750248, 1964178, 5142288, 13462688, 35245778, 92274648, 241578168, 632459858, 1655801408, 4334944368, 11349031698, 29712150728, 77787420488, 203650110738, 533162911728, 1395838624448 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Colin Barker, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (4,-4,1).

FORMULA

a(n)= 4*a(n-1)-4*a(n-2)+a(n-3) = 10*A001519(n+1)-2. G.f.: 2*(4-7x+4x^2)/((1-x)(1-3x+x^2)). - R. J. Mathar, Jan 23 2009

a(n) = 2^(-n)*(-2^(1+n)-(3-sqrt(5))^n*(-5+sqrt(5))+(3+sqrt(5))^n*(5+sqrt(5))). - Colin Barker, Nov 03 2016

MATHEMATICA

LinearRecurrence[{4, -4, 1}, {8, 18, 48}, 30] (* Harvey P. Dale, Nov 04 2015 *)

PROG

(PARI) Vec(2*(4-7*x+4*x^2)/((1-x)*(1-3*x+x^2)) + O(x^30)) \\ Colin Barker, Nov 03 2016

CROSSREFS

Sequence in context: A192311 A300161 A034714 * A109988 A335440 A066721

Adjacent sequences:  A153385 A153386 A153387 * A153389 A153390 A153391

KEYWORD

nonn,easy

AUTHOR

Paul Curtz, Dec 25 2008

EXTENSIONS

More terms from R. J. Mathar, Jan 23 2009

STATUS

approved

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Last modified October 1 07:48 EDT 2020. Contains 337442 sequences. (Running on oeis4.)