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 A255376 #18 Aug 17 2021 20:29:14
%S A255376 0,0,0,0,0,0,1,18,261,3420,42300,504000,5850000,66599991,746999757,
%T A255376 8279995383,90899925399,989998904070,10709984885400,115199800740000,
%U A255376 1232997460650081,13139968482902916,139499617032068526,1475995426741315116,15569946175522343121
%N A255376 Number of strings of n decimal digits that contain at least one string of exactly 6 consecutive "0" digits.
%H A255376 Alois P. Heinz, <a href="/A255376/b255376.txt">Table of n, a(n) for n = 0..1000</a>
%H A255376 <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (20,-100,0,0,0,0,-9,99,-90).
%F A255376 a(0) = a(1) = ... = a(5) = 0, a(6) = 1, a(n) = 9*(10^(n-7) - a(n-7) + sum_{i=6..n-1} a(i)) for n>=7.
%F A255376 G.f.: x^6*(x-1)^2/((10*x-1)*(9*x^8-9*x^7+10*x-1)). - _Alois P. Heinz_, Feb 26 2015
%t A255376 LinearRecurrence[{20,-100,0,0,0,0,-9,99,-90},{0,0,0,0,0,0,1,18,261},30] (* _Harvey P. Dale_, Aug 17 2021 *)
%Y A255376 Cf. A255371-A255375 (for the k=1 through k=5 cases of "exactly k consecutive '0' digits"), A255377-A255380 (for the cases k=7 through k=10).
%K A255376 nonn,base,easy
%O A255376 0,8
%A A255376 _Jon E. Schoenfield_, Feb 22 2015