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

Author

Clark Kimberling, Jul 10 2017

Keywords

• nonn
• easy

Comments

Conjecture: the sequence is strictly increasing.

Crossrefs

Cf. A078140 (includes guide to related sequences).

Programs

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]

Formula

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