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 A284295 #7 Sep 08 2022 08:46:19
%S A284295 1,9,11,19,33,91,99,111,119,133,191,199,313,331,339,393,911,919,933,
%T A284295 991,999,1111,1119,1133,1191,1199,1313,1331,1339,1393,1911,1919,1933,
%U A284295 1991,1999,3113,3131,3139,3193,3311,3319,3333,3391,3399,3913,3931,3939,3993
%N A284295 Numbers n such that product of digits of n is a power of 9.
%C A284295 Supersequence of A284294.
%e A284295 1111 is in the sequence because 1*1*1*1 = 1 = 9^0.
%t A284295 FromDigits /@ Select[Join @@ Map[Tuples[{1, 3, 9}, #] &, Range@ 4], IntegerQ@ Log[9, Times @@ #] &] (* _Michael De Vlieger_, Mar 25 2017 *)
%o A284295 (Magma) Set(Sort([n: n in [1..10000], k in [0..20] | &*Intseq(n) eq 9^k]))
%Y A284295 Cf. Numbers n such that product of digits of n is a power of k for k = 0 - 9: A284375 (k = 0), A002275 (k = 1), A028846 (k = 2), A174813 (k = 3), A284323 (k = 4), A276037 (k = 5), A276038 (k = 6), A276039 (k = 7), A284324 (k = 8), this sequence (k = 9).
%K A284295 nonn,base
%O A284295 1,2
%A A284295 _Jaroslav Krizek_, Mar 25 2017