OFFSET
1,1
COMMENTS
Integers greater than 1 and not in A109421.
EXAMPLE
16 is in the sequence because tau(16)=5 (1,2,4,8,16) and bigomega(16)=4 (2,2,2,2) and so tau(16)/bigomega(16)=5/4.
12 is not in the sequence because tau(12)=6 (1,2,3,4,6,12) and bigomega(12)=3 (2,2,3) and so tau(12)/bigomega(12)=2
MAPLE
with(numtheory): b:=proc(n) if type(tau(n)/bigomega(n), integer)=false then n else fi end: seq(b(n), n=2..300);
MATHEMATICA
PrimeOmega[n_] := Plus @@ FactorInteger[n][[All, 2]]; Select[Range[2, 300], ! IntegerQ[DivisorSigma[0, #]/PrimeOmega[#]] &] (* Jean-François Alcover, May 02 2013 *)
Select[Range[2, 300], !IntegerQ[DivisorSigma[0, #]/PrimeOmega[#]]&] (* Harvey P. Dale, Jun 11 2022 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Emeric Deutsch, Jun 28 2005
STATUS
approved