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A069801 Triangular array in which n-th 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

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Last modified September 23 11:51 EDT 2021. Contains 347612 sequences. (Running on oeis4.)