OFFSET
1,2
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
MATHEMATICA
odFreeQ[n_] := AllTrue[Rest @ Divisors[n], EvenQ[DigitCount[#, 2, 1]] &]; evFreeQ[n_] := AllTrue[Divisors[n], OddQ[DigitCount[#, 2, 1]] &]; m = 100; o = Select[Range[2, m], odFreeQ]; e = Select[Range[m], evFreeQ]; Complement[Range[m], Union @ Select[Times @@@ Tuples[{o, e}], # <= m &]] (* Amiram Eldar, Oct 16 2020 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Irina Gerasimova, Mar 08 2014, following a suggestion from Juri-Stepan Gerasimov.
STATUS
approved