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 A255379 #11 Jun 13 2015 00:55:25
%S A255379 0,0,0,0,0,0,0,0,0,1,18,261,3420,42300,504000,5850000,66600000,
%T A255379 747000000,8280000000,90899999991,989999999757,10709999995383,
%U A255379 115199999925399,1232999998904070,13139999984885400,139499999800740000,1475999997460650000,15569999968482900000
%N A255379 Number of strings of n decimal digits that contain at least one string of exactly 9 consecutive "0" digits.
%H A255379 <a href="/index/Rec#order_12">Index entries for linear recurrences with constant coefficients</a>, signature (20,-100,0,0,0,0,0,0,0,-9,99,-90).
%F A255379 a(0) = a(1) = ... = a(8) = 0, a(9) = 1, a(n) = 9*(10^(n-10) - a(n-10) + sum_{i=9..n-1} a(i)) for n>=10.
%F A255379 G.f.: x^9*(x-1)^2/((10*x-1)*(9*x^11-9*x^10+10*x-1)). - _Alois P. Heinz_, Feb 26 2015
%Y A255379 Cf. A255371-A255378 (for the k=1 through k=8 cases of "exactly k consecutive '0' digits"), A255380 (for the k=10 case).
%K A255379 nonn,base,easy
%O A255379 0,11
%A A255379 _Jon E. Schoenfield_, Feb 22 2015