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 A288236 #13 Mar 12 2025 04:41:17
%S A288236 1,3,5,9,17,30,52,91,160,281,493,865,1518,2664,4675,8204,14397,25265,
%T A288236 44337,77805,136534,239592,420441,737798,1294700,2271961,3986877,
%U A288236 6996242,12277127,21544115,37805987,66342603,116419152,204294349,358499270,629100742
%N A288236 Coefficients in the expansion of 1/([r]-[2*r]*x+[3*r]*x^2-...); [ ]=floor, r=-4/5+sqrt(6).
%C A288236 A288235(k) = a(k) if and only if k <= 56.
%C A288236 Conjecture: the sequence is strictly increasing.
%F A288236 G.f.: 1/(Sum_{k>=0} [(k+1)*r]*(-x)^k), where r = -4/5 + sqrt(6) and [ ] = floor.
%t A288236 r = -4/5 + Sqrt[6];
%t A288236 u = 1000; (* # initial terms from given series *)
%t A288236 v = 100; (* # coefficients in reciprocal series *)
%t A288236 CoefficientList[Series[1/Sum[Floor[r*(k + 1)] (-x)^k, {k, 0, u}], {x, 0, v}], x]
%Y A288236 Cf. A078140 (includes guide to related sequences), A288235.
%K A288236 nonn,easy
%O A288236 0,2
%A A288236 _Clark Kimberling_, Jul 11 2017