OFFSET
1,1
COMMENTS
If k is present so are all m*k, m>1.
The smallest odd number in this sequence is 111546435 = 3*5*7*11*...*23. - T. D. Noe, Jan 15 2004
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
MAPLE
filter:= n -> 3*numtheory:-phi(n) < n:
select(filter, [$1..10000]); # Robert Israel, Jan 13 2020
MATHEMATICA
Select[ Range[437], 3EulerPhi[ # ] < # & ]
PROG
(Magma) [k:k in [1..500]|3*EulerPhi(k) lt k]; // Marius A. Burtea, Jan 13 2020
(PARI) is(n) = 3*eulerphi(n) < n; \\ Amiram Eldar, Apr 07 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Jan 10 2004
STATUS
approved