OFFSET
1,2
COMMENTS
Complement sequence begins 18, 50, 54, 75, 90, 98, ... (A071365).
LINKS
Jens Kruse Andersen, Table of n, a(n) for n = 1..10000
EXAMPLE
12 = 2^2*3^1 is in the sequence, but 18 = 2^1*3^2 is not.
MAPLE
filter:= proc(n)
local F;
F:= ifactors(n)[2];
F:= sort(F, (s, t) -> s[1]>t[1]);
ListTools:-Sorted(map(t -> t[2], F));
end:
select(filter, [$1..100]); # Robert Israel, Aug 18 2014
MATHEMATICA
Select[Range[100], GreaterEqual @@ (FactorInteger[#][[All, 2]]) &]
PROG
(PARI) s=[]; for(n=1, 10^3, m=factor(n)[, 2]; if(vecsort(m, , 4)==m, s=concat(s, n))); s \\ Jens Kruse Andersen, Aug 18 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
Jean-François Alcover, Aug 14 2014
STATUS
approved