|
|
A181488
|
|
Composite Flavius' numbers (A000960) whose divisors are again Flavius' numbers.
|
|
2
|
|
|
39, 49, 91, 133, 763, 15883, 21207, 32761, 180739, 268423, 746607, 2277163, 28604419, 93742347, 13192600483, 124387470307, 3898087261291, 13987912482103, 69089500671469
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
|
|
LINKS
|
|
|
PROG
|
(PARI) A181488(Nmax) = { my(S=[]); for(n=1, Nmax, my(F=n); for(i=1, n-1, F=(n-i)*ceil(F/(n-i)+1)); S=setunion(S, Set(F)); isprime(F) & next; fordiv(F, d, setsearch(S, d)||next(2)); print1(F", "))}
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,changed
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|