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 A201016 #22 May 15 2025 11:45:37
%S A201016 4,14,22,114,122,141,212,221,411,1114,1122,1141,1212,1221,1411,2112,
%T A201016 2121,2211,11114,11122,11141,11212,11221,12112,12121,14111,21112,
%U A201016 41111,111114,111122,111141,111212,111221,111411,112112,112211,114111,121112,121121,121211,122111
%N A201016 Composite numbers whose product of digits is 4.
%C A201016 Complement of A107690 with respect to A199987. Subsequence of A199983 (composite numbers whose multiplicative digital root is 4).
%H A201016 Harvey P. Dale, <a href="/A201016/b201016.txt">Table of n, a(n) for n = 1..1000</a>
%e A201016 Number 122 is in sequence because 1*2*2=4.
%t A201016 Select[Range[125000],CompositeQ[#]&&Times@@IntegerDigits[#]==4&] (* or *) Module[{nn=6,f,t},f=Flatten[Table[Select[FromDigits/@Permutations[PadRight[{4},d,1]],CompositeQ],{d,nn}]];t=Flatten[Table[Select[FromDigits/@Permutations[PadRight[{2,2},d,1]],CompositeQ],{d,nn}]];Join[f,t]]//Sort (* The second program is much faster than the first. *) (* _Harvey P. Dale_, May 15 2025 *)
%Y A201016 Cf. A107690 (primes whose product of digits is 4), A199987 (numbers whose product of digits is 4).
%K A201016 nonn,base
%O A201016 1,1
%A A201016 _Jaroslav Krizek_, Nov 25 2011