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 A332185 #10 Feb 11 2020 08:28:34
%S A332185 5,858,88588,8885888,888858888,88888588888,8888885888888,
%T A332185 888888858888888,88888888588888888,8888888885888888888,
%U A332185 888888888858888888888,88888888888588888888888,8888888888885888888888888,888888888888858888888888888,88888888888888588888888888888,8888888888888885888888888888888
%N A332185 a(n) = 8*(10^(2n+1)-1)/9 - 3*10^n.
%H A332185 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (111,-1110,1000).
%F A332185 a(n) = 8*A138148(n) + 5*10^n = A002282(2n+1) - 3*10^n.
%F A332185 G.f.: (5 + 303*x - 1100*x^2)/((1 - x)(1 - 10*x)(1 - 100*x)).
%F A332185 a(n) = 111*a(n-1) - 1110*a(n-2) + 1000*a(n-3) for n > 2.
%p A332185 A332185 := n -> 8*(10^(2*n+1)-1)/9-3*10^n;
%t A332185 Array[8 (10^(2 # + 1)-1)/9 - 3*10^# &, 15, 0]
%o A332185 (PARI) apply( {A332185(n)=10^(n*2+1)\9*8-3*10^n}, [0..15])
%o A332185 (Python) def A332185(n): return 10**(n*2+1)//9*8-3*10**n
%Y A332185 Cf. A002275 (repunits R_n = (10^n-1)/9), A002282 (8*R_n), A011557 (10^n).
%Y A332185 Cf. A138148 (cyclops numbers with binary digits only), A002113 (palindromes).
%Y A332185 Cf. A332180 .. A332189 (variants with different middle digit 0, ..., 9).
%Y A332185 Cf. A332115 .. A332195 (variants with different "wing" digit 1, ..., 9).
%K A332185 nonn,base,easy
%O A332185 0,1
%A A332185 _M. F. Hasler_, Feb 08 2020