OFFSET
1,1
EXAMPLE
a(3)=1158 because it is squarefree and 1157 = 13*89 is brilliant as is
1159 = 19*61.
MATHEMATICA
sfnQ[{a_, b_, c_}]:=Module[{a1=FactorInteger[a][[All, 1]], c1= FactorInteger[ c][[All, 1]]}, Length[a1]==Length[c1]==2&&PrimeOmega[a]== PrimeOmega[c] == 2&&IntegerLength[a1[[1]]]==IntegerLength[a1[[2]]]&&IntegerLength[ c1[[1]]] == IntegerLength[c1[[2]]]&&SquareFreeQ[b]]; Join[{5}, Select[ Partition[Range[120000], 3, 1], sfnQ][[All, 2]]] (* Harvey P. Dale, Nov 26 2016 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Jason Earls, Jul 18 2003
STATUS
approved