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

1,4

Links

Table of n, a(n) for n=1..99.

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 *)

Crossrefs

Sequence in context: A352570 A277855 A136662 * A372516 A177718 A057515

Adjacent sequences: A023592 A023593 A023594 * A023596 A023597 A023598

Keyword

nonn

Author

Clark Kimberling

Status

approved