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A097115 Expansion of (1 + 11*x - 90*x^2 - 1100*x^3)/(1 - 201*x^2 + 10100*x^4). 0
1, 11, 111, 1111, 12211, 112211, 1333311, 11333311, 144664411, 1144664411, 15611105511, 115611105511, 1676721656611, 11676721656611, 179348887317711, 1179348887317711, 19114237619088811, 119114237619088811 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..17.

Index entries for linear recurrences with constant coefficients, signature (0, 201,0,-10100).

FORMULA

G.f.: 11*(1+x)/(1-101*x^2) - 10/(1-100*x^2);

a(n) = 201*a(n-2) - 10100*a(n-4);

a(n) = (11/2 + 11*sqrt(101)/202)*sqrt(101)^n + (11/2 - 11*sqrt(101)/202)*(-sqrt(101))^n - 10^(n+1)*(1+(-1)^n)/2;

a(n) = Sum_{k=0..n} binomial(floor(n/2), floor(k/2))*10^k.

CROSSREFS

Sequence in context: A294348 A078998 A078191 * A134732 A166747 A015456

Adjacent sequences:  A097112 A097113 A097114 * A097116 A097117 A097118

KEYWORD

easy,nonn

AUTHOR

Paul Barry, Jul 25 2004

STATUS

approved

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Last modified October 14 18:28 EDT 2019. Contains 328022 sequences. (Running on oeis4.)