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A088688 Binomial transform of A088689. 0
0, 1, 3, 6, 12, 27, 63, 141, 297, 594, 1146, 2169, 4095, 7827, 15291, 30582, 62256, 127791, 262143, 534129, 1078101, 2156202, 4282878, 8477181, 16777215, 33288711, 66311703, 132623406, 266043972, 534479427, 1073741823, 2154658101 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..31.

FORMULA

a(n) = 2^n - cos(Pi*n/3) - 3^(n/2)*sin(Pi*n/6)/sqrt(3).

O.g.f.: -x(1-3x+3x^2+x^3)/[(2x-1)(x^2-x+1)(3x^2-3x+1)]. - R. J. Mathar, Apr 02 2008

MATHEMATICA

Table[Sum[Binomial[n, k] * Mod[k*Floor[3*(k+1)/2] - 2*k, 3], {k, 0, n}], {n, 0, 40}] (* Vaclav Kotesovec, Oct 30 2017 *)

CROSSREFS

Cf. A001045.

Sequence in context: A054190 A268681 A101013 * A290997 A052103 A072168

Adjacent sequences:  A088685 A088686 A088687 * A088689 A088690 A088691

KEYWORD

easy,nonn

AUTHOR

Paul Barry, Oct 06 2003

STATUS

approved

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Last modified April 14 00:42 EDT 2021. Contains 342941 sequences. (Running on oeis4.)