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 A168098 #13 Jun 29 2023 12:52:58 %S A168098 8,9,10,11,12,13,14,15,16,17,17,17,17,17,17,17,17,17,17,17,17,17,17, %T A168098 17,17,17,17,17,17,17,17,17,17,17,17,17,17,17,17,17,17,17,17,17,17,17, %U A168098 17,17,17,17,17,17,17,17,17,17,17,17 %N A168098 a(n) = number of natural numbers m such that n - 8 <= m <= n + 8. %C A168098 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 A168098 <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (1). %F A168098 a(n) = 8 + n for 0 <= n <= 8, a(n) = 17 for n >= 9. %F A168098 G.f.: (8 - 7*x - x^10)/(1 - x)^2. - _G. C. Greubel_, Jul 12 2016 %t A168098 CoefficientList[Series[(8 - 7*x - x^10)/(1 - x)^2, {x, 0, 25}], x] (* _G. C. Greubel_, Jul 12 2016 *) %Y A168098 Cf. A000027. %K A168098 nonn,less %O A168098 0,1 %A A168098 _Jaroslav Krizek_, Nov 18 2009