[seqfan] W and M numbers (was: Any digit of F is the sum of two other digits of F)

[Eric Angelini]

Hello SeqFans, 

A "W number" is an integer W having the property that every digit of W is the sum of two or more digits of W.
Example:
10070231 is a W number as:
- each digit "1" is the sum of another "1" and a "0";
- each digit "0" is the sum of the two other "0"s;
- the digit "7" is the sum of the digits 1+2+3+1;
- the digit "2" is the sum of the digits 1+1;
- the digit "3" is the sum of the digits 2+1.
Sequence:
The W(n) sequence of "W numbers" starts like this:
W(n) = 10001, 10010, 10100, 11000, 20002, 20020, 20200, 22000, 30003, 30030, 30300, 33000, 40004, 40040, 40400, 44000, 50005, 50050, 50500, 55000, 60006, 60060, 60600, 66000, 70007, 70070, 70700, 77000, 80008, 80080, 80800, 88000, 90009, 90090, 90900, 99000, 100001, 100010, 100011, 100012, 100021, 100100, 100101, 100102, 100110, 100120, ...

(...)

"M numbers" (M for Multiply) are here:
http://www.cetteadressecomportecinquantesignes.com/Wnumbers.htm

Best,
É.