|
| |
|
|
A001104
|
|
Numbers n such that n / product of digits of n is a square.
|
|
0
|
|
|
|
1, 2, 3, 4, 5, 6, 7, 8, 9, 135, 144, 384, 1575, 1715, 6144, 6912, 11664, 14112, 16224, 18816, 23328, 26136, 31212, 41616, 82944, 83232, 93312, 131424, 131712, 186624, 248832, 371112, 1168128, 2214144, 2239488, 2333772, 3321216, 3881472, 6642432
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,2
|
|
|
LINKS
|
|
|
|
MATHEMATICA
|
Select[Range[665*10^4], IntegerQ[Sqrt[#/Times@@IntegerDigits[#]]]&]// Quiet (* Harvey P. Dale, May 09 2019 *)
|
|
|
PROG
|
(PARI) isok(n) = {digs = digits(n); q = prod(i=1, #digs, digs[i]); (q != 0) && (n % q == 0) && issquare(n/q); } \\ Michel Marcus, Sep 04 2013
|
|
|
CROSSREFS
|
|
|
|
KEYWORD
|
nonn,base
|
|
|
AUTHOR
|
|
|
|
STATUS
|
approved
|
| |
|
|
