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A097334 Sum k=0..n, C(n-k, floor(k/2))2^k. 4
1, 3, 3, 7, 19, 31, 59, 135, 259, 495, 1035, 2071, 4051, 8191, 16475, 32679, 65443, 131343, 262059, 523831, 1049203, 2097439, 4192763, 8389575, 16779331, 33550383, 67108683, 134226007, 268427539, 536862271, 1073766299, 2147476455 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Harvey P. Dale, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (1,0,4)

FORMULA

G.f. : (1+2x)/((1-2*x)*(1+x+2*x^2)); a(n)=a(n-1)+4a(n-3).

MATHEMATICA

Table[Sum[Binomial[n-k, Floor[k/2]]2^k, {k, 0, n}], {n, 0, 40}] (* or *) LinearRecurrence[{1, 0, 4}, {1, 3, 3}, 40] (* Harvey P. Dale, May 17 2021 *)

CROSSREFS

Cf. A089977, A097333, A097335.

Sequence in context: A036574 A174034 A081486 * A214496 A046631 A100666

Adjacent sequences:  A097331 A097332 A097333 * A097335 A097336 A097337

KEYWORD

easy,nonn

AUTHOR

Paul Barry, Aug 05 2004

STATUS

approved

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Last modified December 5 20:39 EST 2021. Contains 349558 sequences. (Running on oeis4.)