SumPrimeDivisors[n_] := Total[First /@ FactorInteger[n]] RuthAaron[n_] := SumPrimeDivisors[n] == SumPrimeDivisors[n + 1] SumPrimeFactors[n_] := Total[First[#] * Last[#] & /@ FactorInteger[n]] RuthAaronFactors[n_] := SumPrimeFactors[n] == SumPrimeFactors[n + 1] RuthAaronSeq := Select[Range[100000], RuthAaron] RuthAaronFactorSeq := Select[Range[100000], RuthAaronFactors] Print["30 Ruth Aaron numbers:"] Print[Take[RuthAaronSeq, 30]] Print["\n30 Ruth Aaron factor numbers:"] Print[Take[RuthAaronFactorSeq, 30]]