A145193 Omega(6n-1) + Omega(6n+1).

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

Offset: 1

Author

Arran Fernandez, Oct 03 2008

Keywords

• nonn
• easy

Examples

			For n=1, Omega(6n-1) + Omega(6n+1) = Omega(5) + Omega(7) = 1+1 = 2, so a(1)=2.
		

Links

• Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A145194.

Programs

Mathematica

For[x=6, x<601, x+=6,S=0;T=0;For[k=1, k< Length[FactorInteger[x-1]]+1,k++,S+= FactorInteger[x-1][[k]][[2]]];For[m=1, mHarvey P. Dale, May 22 2013 *)

PARI

a(n) = bigomega(6*n-1) + bigomega(6*n+1); \\ Michel Marcus, Sep 04 2013

Formula

a(n) = A001222(6n-1) + A001222(6n+1). - Michel Marcus, Sep 04 2013

Extensions

More terms from Michel Marcus, Sep 04 2013