cp's OEIS Frontend

A069801 Triangular array in which the n-th row consists of numbers with digit product n arranged in increasing numerical order; row consists of 0 if no such numbers exist.

%I A069801 #15 Jul 02 2022 16:08:38
%S A069801 1,2,3,4,22,5,6,23,32,7,8,24,42,222,9,33,25,52,0,26,34,43,62,223,232,
%T A069801 322,0,27,72,35,53,28,44,82,224,242,422,2222,0,29,36,63,92,233,323,
%U A069801 332,0,45,54,225,252,522,37,73,0,0,38,46,64,83,226,234,243,262
%N A069801 Triangular array in which the n-th row consists of numbers with digit product n arranged in increasing numerical order; row consists of 0 if no such numbers exist.
%C A069801 1 is not allowed as a digit, except in the first row.
%C A069801 If n has any prime factor other than 2,3,5 or 7 then a(n) = 0.
%H A069801 Alois P. Heinz, <a href="/A069801/b069801.txt">Rows n = 1..1000, flattened</a>
%e A069801 Triangular array begins:
%e A069801 1;
%e A069801 2;
%e A069801 3;
%e A069801 4,  22;
%e A069801 5;
%e A069801 6,  23, 32;
%e A069801 7;
%e A069801 8,  24, 42, 222;
%e A069801 9,  33;
%e A069801 25, 52;
%e A069801 0;
%e A069801 26, 34, 43,  62, 223, 232, 322;
%Y A069801 Cf. A069800.
%K A069801 nonn,tabf,base,look
%O A069801 1,2
%A A069801 _Amarnath Murthy_, Apr 13 2002
%E A069801 Corrected and extended by _Alois P. Heinz_, Sep 24 2013