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 A168094 #14 Jun 29 2023 12:49:00 %S A168094 4,5,6,7,8,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, %T A168094 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, %U A168094 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9 %N A168094 a(n) = number of natural numbers m such that n - 4 <= m <= n + 4. %C A168094 Generalization: If a(n,k) = number of natural numbers m such that n - k <= m <= n + k (k >= 1) then a(n,k) = a(n-1,k) + 1 = n + k for 0 <= n <= k, a(n,k) = a(n-1,k) = 2k + 1 for n >= k + 1 (see, e.g., A158799). %H A168094 <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (1). %F A168094 a(n) = 4 + n for 0 <= n <= 4, a(n) = 9 for n >= 4. %F A168094 G.f.: (4 - 3*x - x^6)/(1 - x)^2. - _G. C. Greubel_, Jul 12 2016 %t A168094 CoefficientList[Series[(4 - 3*x - x^6)/(1 - x)^2, {x, 0, 25}], x] (* _G. C. Greubel_, Jul 12 2016 *) %Y A168094 Cf. A000027. %K A168094 nonn,less %O A168094 0,1 %A A168094 _Jaroslav Krizek_, Nov 18 2009