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A145193
Omega(6n-1) + Omega(6n+1).
3
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
1,1
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = A001222(6n-1) + A001222(6n+1). - Michel Marcus, Sep 04 2013
EXAMPLE
For n=1, Omega(6n-1) + Omega(6n+1) = Omega(5) + Omega(7) = 1+1 = 2, so a(1)=2.
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, m<Length[FactorInteger[x+1]]+1, m++, T+= FactorInteger[x+1][[m]][[2]]]; Print[x/6, " ", S+T]]
Table[Total[PrimeOmega/@(6n+{1, -1})], {n, 60}] (* Harvey P. Dale, May 22 2013 *)
PROG
(PARI) a(n) = bigomega(6*n-1) + bigomega(6*n+1); \\ Michel Marcus, Sep 04 2013
CROSSREFS
Cf. A145194.
Sequence in context: A318490 A071215 A164024 * A292585 A175872 A143117
KEYWORD
nonn,easy
AUTHOR
Arran Fernandez, Oct 03 2008
EXTENSIONS
More terms from Michel Marcus, Sep 04 2013
STATUS
approved