This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A288229 #8 Mar 12 2025 04:40:23
%S A288229 1,3,5,9,18,36,72,144,287,570,1132,2250,4473,8892,17676,35137,69847,
%T A288229 138845,276002,548649,1090629,2168001,4309649,8566912,17029689,
%U A288229 33852374,67293256,133768530,265911039,528589801,1050754338,2088736250,4152082903,8253695235
%N A288229 Coefficients of 1/(Sum_{k>=0} [(k+1)*r]*(-x)^k), where r = Pi/2 and [ ] = floor.
%C A288229 Conjecture: the sequence is strictly increasing.
%F A288229 G.f.: 1/(Sum_{k>=0} [(k+1)*r]*(-x)^k), where r = Pi/2 and [ ] = floor.
%t A288229 r = Pi/2;
%t A288229 u = 1000; (* # initial terms from given series *)
%t A288229 v = 100; (* # coefficients in reciprocal series *)
%t A288229 CoefficientList[Series[1/Sum[Floor[r*(k + 1)] (-x)^k, {k, 0, u}], {x, 0, v}], x]
%Y A288229 Cf. A078140 (includes guide to related sequences).
%K A288229 nonn,easy
%O A288229 0,2
%A A288229 _Clark Kimberling_, Jul 10 2017