|
|
A322840
|
|
Positive integers n with fewer prime factors (counted with multiplicity) than n + 1.
|
|
3
|
|
|
1, 3, 5, 7, 11, 13, 15, 17, 19, 23, 26, 29, 31, 35, 37, 39, 41, 43, 47, 49, 51, 53, 55, 59, 61, 62, 63, 65, 67, 69, 71, 73, 74, 77, 79, 83, 87, 89, 91, 95, 97, 99, 101, 103, 107, 109, 111, 113, 115, 119, 123, 125, 127, 129, 131, 134, 137, 139, 143, 146, 149
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
LINKS
|
|
|
EXAMPLE
|
49 = 7*7 has two prime factors, while 50 = 2*5*5 has three, so 49 belongs to the sequence.
|
|
MATHEMATICA
|
Select[Range[100], PrimeOmega[#]<PrimeOmega[#+1]&]
Position[Partition[PrimeOmega[Range[150]], 2, 1], _?(#[[1]]< #[[2]]&), 1, Heads->False]//Flatten (* Harvey P. Dale, Sep 23 2021 *)
|
|
PROG
|
(PARI) isok(n) = bigomega(n) < bigomega(n+1); \\ Michel Marcus, Dec 29 2018
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|