OFFSET
1,1
COMMENTS
a(k)=A070011(k) for 0<k<=25, A070011(26)=120 is not a term, as 120=5*3*2^3 having only odd exponents (A002035(85)=120), and a(54)=240 is not a term of A070011, as from 240=5*3*2^4 follows that A001222(240)/A001221(240)=6/3=2 is an integer.
The asymptotic density of this sequence is 1 - A065463 = 0.2955577990... - Amiram Eldar, Sep 18 2022
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
MATHEMATICA
oeeQ[n_]:=Module[{fi=Transpose[FactorInteger[n]][[2]]}, Count[fi, _?OddQ]>0 && Count[fi, _?EvenQ]>0]; Select[Range[250], oeeQ] (* Harvey P. Dale, Jun 21 2015 *)
PROG
(Haskell)
a072588 n = a072588_list !! (n-1)
a072588_list = filter f [1..] where
f x = any odd es && any even es where es = a124010_row x
-- Reinhard Zumkeller, Nov 15 2012
(PARI) is(n)=#Set(factor(n)[, 2]%2)==2 \\ Charles R Greathouse IV, Oct 16 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Jun 23 2002
STATUS
approved