A288229 Coefficients of 1/(Sum_{k>=0} [(k+1)*r](-x)^k), where r = Pi/2 and [ ] = floor.

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

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