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A288229 Coefficients of 1/(Sum_{k>=0} [(k+1)*r](-x)^k), where r = Pi/2 and [ ] = floor. 2
1, 3, 5, 9, 18, 36, 72, 144, 287, 570, 1132, 2250, 4473, 8892, 17676, 35137, 69847, 138845, 276002, 548649, 1090629, 2168001, 4309649, 8566912, 17029689, 33852374, 67293256, 133768530, 265911039, 528589801, 1050754338, 2088736250, 4152082903, 8253695235 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Conjecture: the sequence is strictly increasing.

LINKS

Table of n, a(n) for n=0..33.

FORMULA

G.f.:  1/(Sum_{k>=0} [(k+1)*r)](-x)^k), where r = Pi/2 and [ ] = floor.

MATHEMATICA

r = Pi/2;

u = 1000; (* # initial terms from given series *)

v = 100;   (* # coefficients in reciprocal series *)

CoefficientList[Series[1/Sum[Floor[r*(k + 1)] (-x)^k, {k, 0, u}], {x, 0, v}], x]

CROSSREFS

Cf. A078140 (includes guide to related sequences).

Sequence in context: A289262 A288231 A279592 * A293332 A288135 A279634

Adjacent sequences:  A288226 A288227 A288228 * A288230 A288231 A288232

KEYWORD

nonn,easy

AUTHOR

Clark Kimberling, Jul 10 2017

STATUS

approved

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Last modified July 25 03:53 EDT 2021. Contains 346283 sequences. (Running on oeis4.)