login
A174800
Number whose product of digits is a square.
0
0, 1, 4, 9, 10, 11, 14, 19, 20, 22, 28, 30, 33, 40, 41, 44, 49, 50, 55, 60, 66, 70, 77, 80, 82, 88, 90, 91, 94, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 114, 119, 120, 122, 128, 130, 133, 140, 141, 144, 149, 150, 155, 160, 166, 170, 177, 180, 182, 188, 190, 191, 194, 199, 200
OFFSET
0,3
COMMENTS
Differs from A062371 in that here the digit 0 is included in the product and so every number containing a zero belongs to this sequence. - D. S. McNeil, Dec 01 2010
EXAMPLE
149 is in the sequence because 1*4*9 = 6^2; 20 is in the sequence because 2*0 = 0^2.
MATHEMATICA
Select[Range[1000], IntegerQ[Sqrt[Times @@ (IntegerDigits[#])]] &]
CROSSREFS
Cf. A062371.
Sequence in context: A020673 A166498 A266297 * A062371 A046030 A125726
KEYWORD
nonn,base
AUTHOR
Michel Lagneau, Dec 01 2010
STATUS
approved