A023595 a(n) = sum of exponents in prime-power factorization of 2*prime(n)+1.

1, 1, 1, 2, 1, 3, 2, 2, 1, 1, 3, 3, 1, 2, 2, 1, 2, 2, 4, 2, 3, 2, 1, 1, 3, 2, 3, 2, 2, 1, 3, 1, 3, 3, 2, 2, 4, 2, 2, 1, 1, 3, 1, 3, 2, 3, 3, 2, 3, 4, 1, 1, 3, 1, 2, 2, 3, 2, 3, 1, 5, 1, 3, 2, 3, 2, 3, 5, 2, 2, 2, 1, 4, 3, 3, 2, 2, 3, 2, 4, 1, 2, 1, 3, 2, 1, 2, 3, 2, 3, 3, 2, 4, 1, 4, 2, 1, 2, 2

Offset: 1

Author

Clark Kimberling

Keywords

• nonn

Programs

Mathematica

Array[Plus@@Last/@FactorInteger[2*Prime[ # ]+1]&,6! ] (* Vladimir Joseph Stephan Orlovsky, Feb 28 2010 *)
Total[FactorInteger[#][[All,2]]]&/@(2*Prime[Range[100]]+1) (* Harvey P. Dale, Oct 02 2017 *)