|
Search: id:A063139
|
|
|
| A063139 |
|
Composite numbers which in base 3 contain their largest proper factor as a substring. |
|
+0
1
|
|
| 9, 15, 21, 27, 33, 39, 45, 49, 51, 57, 63, 69, 75, 81, 87, 93, 99, 105, 111, 117, 123, 129, 135, 141, 147, 153, 159, 165, 171, 177, 183, 189, 195, 201, 207, 213, 219, 225, 231, 237, 243, 249, 255, 261, 267, 273, 279, 285, 291, 297
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
MATHEMATICA
|
Do[ If[ !PrimeQ[ n ] && StringPosition[ ToString[ FromDigits[ IntegerDigits[ n, 3 ] ] ], ToString[ FromDigits[ IntegerDigits[ Divisors[ n ] [ [ -2 ] ], 3 ] ] ] ] != {}, Print[ n ] ], {n, 2, 10^2} ]
|
|
CROSSREFS
|
Cf. A062238.
Adjacent sequences: A063136 A063137 A063138 this_sequence A063140 A063141 A063142
Sequence in context: A025045 A107987 A031879 this_sequence A097636 A007962 A061254
|
|
KEYWORD
|
base,nonn
|
|
AUTHOR
|
Robert G. Wilson v (rgwv(AT)rgwv.com), Aug 08 2001
|
|
|
Search completed in 0.002 seconds
|
