OFFSET
1,2
COMMENTS
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..1000 from Zak Seidov)
EXAMPLE
108 = 2^2*3^3 has one even and one odd exponent in its factorization and therefore qualifies.
MATHEMATICA
Reap[Do[fi=FactorInteger[n]; la=Mod[Last/@fi, 2]; If[Count[la, 1]==Count[la, 0], Sow[n]] , {n, 1, 10000}]][[2, 1]] (* Zak Seidov, Mar 04 2011 *)
eoeQ[n_]:=Module[{f=FactorInteger[n][[All, 2]]}, Count[ f, _?OddQ]== Length[ f]/2]; Join[{1}, Select[Range[400], eoeQ]] (* Harvey P. Dale, Sep 23 2016 *)
PROG
(Magma) IsA187039:=func< n | #[ a: a in P | IsEven(a) ] eq #[ a: a in P | IsOdd(a) ] where P is [ g[2]: g in F ] where F is Factorization(n) >; [ n: n in [1..500] | IsA187039(n) ]; // Klaus Brockhaus, Mar 04 2011
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Shevelev, Mar 02 2011
STATUS
approved