|
Search: id:A051280
|
|
|
| A051280 |
|
n=k/d(k) has exactly 3 solutions, where d(k) = number of divisors of k. |
|
+0
8
|
|
| 3, 25, 40, 49, 54, 121, 125, 135, 140, 169, 189, 216, 220, 250, 260, 289, 297, 340, 351, 361, 375, 380, 400, 459, 460, 500, 513, 529, 580, 620, 621, 675, 729, 740, 770, 783, 820, 837, 841, 860, 875, 882, 910, 940, 961, 999, 1060, 1107, 1152, 1161, 1180, 1188, 1190
(list; graph; listen)
|
|
|
OFFSET
|
0,1
|
|
|
EXAMPLE
|
There are exactly 3 numbers k, 9, 18 and 24, with k/d(k)=3.
|
|
CROSSREFS
|
Cf. A033950, A036763, A051278, A051279, A051346.
Sequence in context: A076962 A129599 A042899 this_sequence A145609 A120285 A041897
Adjacent sequences: A051277 A051278 A051279 this_sequence A051281 A051282 A051283
|
|
KEYWORD
|
nonn,easy,nice
|
|
AUTHOR
|
N. J. A. Sloane (njas(AT)research.att.com), R. K. Guy, David W. Wilson (davidwwilson(AT)comcast.net)
|
|
|
Search completed in 0.002 seconds
|
