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 A288234 #12 Mar 12 2025 04:40:37
%S A288234 1,3,5,9,17,30,52,91,160,281,493,865,1518,2664,4675,8204,14398,25271,
%T A288234 44356,77853,136647,239844,420976,738898,1296915,2276349,3995455,
%U A288234 7012834,12308945,21604693,37920614,66558359,116823399,205048721,359902025,631700929
%N A288234 Coefficients in the expansion of 1/([r]-[2*r]*x+[3*r]*x^2-...); [ ]=floor, r=-1+sqrt(7).
%C A288234 Conjecture: the sequence is strictly increasing.
%e A288234 G.f.: 1/(Sum_{k>=0} [(k+1)*r]*(-x)^k), where r = -1+sqrt(7) and [ ] = floor.
%t A288234 r = -1 + Sqrt[7];
%t A288234 u = 1000; (* # initial terms from given series *)
%t A288234 v = 100; (* # coefficients in reciprocal series *)
%t A288234 CoefficientList[Series[1/Sum[Floor[r*(k + 1)] (-x)^k, {k, 0, u}], {x, 0, v}], x]
%Y A288234 Cf. A078140 (includes guide to related sequences).
%K A288234 nonn,easy
%O A288234 0,2
%A A288234 _Clark Kimberling_, Jul 11 2017