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 A284963 #12 Sep 08 2022 08:46:19
%S A284963 3,8,33,38,83,88,333,338,383,388,833,838,883,888,3333,3338,3383,3388,
%T A284963 3833,3838,3883,3888,8333,8338,8383,8388,8833,8838,8883,8888,33333,
%U A284963 33338,33383,33388,33833,33838,33883,33888,38333,38338,38383,38388,38833,38838
%N A284963 Numbers with digits 3 and 8 only.
%t A284963 Table[FromDigits/@Tuples[{3,8},n],{n,5}]//Flatten (* _Harvey P. Dale_, Mar 23 2021 *)
%o A284963 (Magma) [n: n in [1..100000] | Set(IntegerToSequence(n, 10)) subset {3, 8}]
%Y A284963 Prime terms are in A020464.
%Y A284963 Numbers with digits 3 and k only for k = 0 - 2 and 4 - 9: A169966 (k = 0), A032917 (k = 1), A032810 (k = 2), A032834 (k = 4), A284379 (k = 5), A284633 (k = 6), A143967 (k = 7), this sequence (k = 8), A284964 (k = 9).
%K A284963 nonn,base
%O A284963 1,1
%A A284963 _Jaroslav Krizek_, Apr 06 2017