

A069801


Triangular array in which nth row consists of numbers with digit product n arranged in increasing numerical order; row consists of 0 in no such numbers exist.


2



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, 322, 0, 27, 72, 35, 53, 28, 44, 82, 224, 242, 422, 2222, 0, 29, 36, 63, 92, 233, 323, 332, 0, 45, 54, 225, 252, 522, 37, 73, 0, 0, 38, 46, 64, 83, 226, 234, 243, 262
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,2


COMMENTS

1 is not allowed as a digit, except in first row.
If n has any prime factor other than 2,3,5 or 7 then a(n) = 0.


LINKS

Alois P. Heinz, Rows n = 1..1000, flattened


EXAMPLE

Triangular array begins:
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, 322;


CROSSREFS

Cf. A069800.
Sequence in context: A109302 A081480 A070841 * A019074 A019075 A006709
Adjacent sequences: A069798 A069799 A069800 * A069802 A069803 A069804


KEYWORD

nonn,tabf,base,look


AUTHOR

Amarnath Murthy, Apr 13 2002


EXTENSIONS

Corrected and extended by Alois P. Heinz, Sep 24 2013


STATUS

approved



