cp's OEIS Frontend

A199987 Numbers with digital product = 4.

%I A199987 #15 Jan 13 2021 17:58:48
%S A199987 4,14,22,41,114,122,141,212,221,411,1114,1122,1141,1212,1221,1411,
%T A199987 2112,2121,2211,4111,11114,11122,11141,11212,11221,11411,12112,12121,
%U A199987 12211,14111,21112,21121,21211,22111,41111,111114,111122,111141,111212,111221,111411
%N A199987 Numbers with digital product = 4.
%C A199987 Subsequence of A034051.
%H A199987 Robert Israel, <a href="/A199987/b199987.txt">Table of n, a(n) for n = 1..10000</a>
%p A199987 f:= proc(d) local b,i,t;
%p A199987    b:= (10^d-1)/9;
%p A199987    op(sort([seq(b+3*10^i,i=0..d-1),
%p A199987     seq(b+10^t[1]+10^t[2],t=combinat:-choose([$0..d-1],2))]))
%p A199987 end proc:
%p A199987 seq(f(d),d=1..6); # _Robert Israel_, Jan 13 2021
%t A199987 Select[Range[200000], Times @@ IntegerDigits[#] == 4 &] (* _T. D. Noe_, Nov 16 2011 *)
%K A199987 nonn,base
%O A199987 1,1
%A A199987 _Jaroslav Krizek_, Nov 13 2011