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