|
| |
|
|
A050704
|
|
Composite numbers with property that n minus sum of prime factors of n is prime.
|
|
2
| |
|
|
8, 9, 10, 12, 14, 15, 20, 21, 26, 28, 33, 35, 38, 39, 40, 44, 48, 51, 54, 56, 62, 65, 68, 69, 76, 77, 80, 86, 88, 91, 93, 95, 96, 111, 112, 116, 122, 123, 124, 129, 133, 136, 146, 148, 152, 159, 161, 176, 188, 189, 198, 201, 203, 206, 209, 210, 213, 215, 217, 218
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,1
|
|
|
COMMENTS
| Prime factors are totaled with multiplicity, e.g., 8 = 2*2*2 so the sum of the prime factors of 8 = 6. [From Harvey P. Dale, June 14 2011]
|
|
|
EXAMPLE
| E.g. 161 = 7.23 so 161 - (7+23) = 161 - 30 = 131 and prime.
|
|
|
MATHEMATICA
| Select[Range[250], PrimeQ[#-Total[Times@@@FactorInteger[#]]]&] (* From Harvey P. Dale, June 14 2011 *)
|
|
|
CROSSREFS
| Cf. A050703-A050710.
Sequence in context: A152870 A181723 A078893 * A024884 A031009 A120184
Adjacent sequences: A050701 A050702 A050703 * A050705 A050706 A050707
|
|
|
KEYWORD
| nonn,nice
|
|
|
AUTHOR
| Patrick De Geest (pdg(AT)worldofnumbers.com), Aug 15 1999.
|
| |
|
|
