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 A291663 #18 Dec 21 2018 12:51:23
%S A291663 1,8,11,18,21,28,31,38,41,48,51,58,61,68,71,78,81,88,91,98,100,101,
%T A291663 102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,
%U A291663 119,120,121,122,123,124,125,126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,144,145,146,147,148,149
%N A291663 Numbers beginning with a vowel in Danish.
%C A291663 The sequence of words is: en, otte, elleve, atten, enogtyve, otteogtyve, enogtredive, otteogtredive, enogfyrre, otteogfyrre, enoghalvtreds, otteoghalvtreds, enogtreds, otteogtreds, enoghalvfjerds, ...
%H A291663 Halfdan Skjerning, <a href="/A291663/b291663.txt">Table of n, a(n) for n = 1..150</a>
%H A291663 Brady Haran and Tom Scott, <a href="https://www.youtube.com/watch?v=l4bmZ1gRqCc">58 and other Confusing Numbers</a>, Numberphile video (2015)
%H A291663 Wikipedia, <a href="https://en.wikipedia.org/wiki/List_of_numbers_in_various_languages">List of numbers in various languages</a>
%F A291663 All numbers beginning with '1' or '8', except for two-digit numbers that do not end in '1' or '8'.
%t A291663 Select[Range@ 149, With[{d = IntegerDigits@ #}, MemberQ[{1, 8}, If[Length@ d == 2, First@ Reverse@ d, First@ d]]] &] (* _Michael De Vlieger_, Aug 30 2017 *)
%Y A291663 Cf. A000861, A079741, A098060, A247751, A291621.
%K A291663 nonn,easy,word
%O A291663 1,2
%A A291663 _Halfdan Skjerning_, Aug 29 2017