A097118 - OEIS

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A097118

Expansion of (1+x)/((1-x)^2-5x^3).

1, 1, 1, 6, 16, 31, 76, 201, 481, 1141, 2806, 6876, 16651, 40456, 98641, 240081, 583801, 1420726, 3458056, 8414391, 20474356, 49824601, 121246801, 295040781, 717957766, 1747108756, 4251463651, 10345607376, 25175294881, 61262300641

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,4

LINKS

Table of n, a(n) for n=0..29.

Index entries for linear recurrences with constant coefficients, signature (2,-1,5).

FORMULA

G.f. : (1+x)/(1-2x+x^2-5x^3); a(n)=2a(n-1)-a(n-2)+5a(n-3); a(n)=sum{k=0..floor(n/2), binomial(n-k, 2k)5^k }.

CROSSREFS

Sequence in context: A301723 A288113 A276917 * A369548 A296957 A341276

Adjacent sequences: A097115 A097116 A097117 * A097119 A097120 A097121

KEYWORD

easy,nonn

AUTHOR

Paul Barry, Jul 25 2004

STATUS

approved