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 A043521 #22 Aug 18 2021 09:30:03
%S A043521 8,18,28,38,48,58,68,78,80,81,82,83,84,85,86,87,89,98,108,118,128,138,
%T A043521 148,158,168,178,180,181,182,183,184,185,186,187,189,198,208,218,228,
%U A043521 238,248,258,268,278,280,281,282,283,284,285,286,287,289,298,308,318
%N A043521 Numbers having one 8 in base 10.
%H A043521 Enrique Pérez Herrero, <a href="/A043521/b043521.txt">Table of n, a(n) for n = 1..2000</a>
%H A043521 <a href="/index/Ar#10-automatic">Index entries for 10-automatic sequences</a>.
%t A043521 Select[Range[300],DigitCount[#,10,8]==1&] (* _Harvey P. Dale_, Jan 06 2012 *)
%o A043521 (PARI) is(n)=my(d=digits(n)); sum(i=1,#d, d[i]==8)==1 \\ _Charles R Greathouse IV_, Feb 12 2017
%o A043521 (Python)
%o A043521 def ok(n): return str(n).count('8') == 1
%o A043521 print(list(filter(ok, range(320)))) # _Michael S. Branicky_, Aug 18 2021
%Y A043521 Subsequence of A011538.
%Y A043521 Cf. A043489, A043493, A043497, A043501, A043505, A043509, A043513, A043517, A043525, A011538.
%K A043521 nonn,base,easy
%O A043521 1,1
%A A043521 _Clark Kimberling_