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A145194
Least k for which Omega(6k-1) + Omega(6k+1) >= n.
1
1, 1, 4, 20, 41, 104, 479, 1146, 7603, 16521, 91146, 188021, 188021, 1861979, 14122396, 43294271, 203450521, 203450521, 5877278646, 5900065104, 16886393229
OFFSET
1,3
COMMENTS
a(22) <= 170499674479. a(23) <= 1307169596354. a(24) <= 3178914388021. a(25) <= 3178914388021. a(26) <= 43614705403646 [From Donovan Johnson, Feb 17 2010]
EXAMPLE
When k=1,2 and 3, Omega(6k-1) + Omega(6k+1) = 2. When k=4, Omega(6k-1) + Omega(6k+1) = 3, so a(3)=4.
MATHEMATICA
Maxie=0; For[x=6, x<10000001, 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]]]; If[S+T>Maxie, Print[x/6, " ", S+T]; Maxie=S+T]]
CROSSREFS
Sequence in context: A072977 A341895 A163365 * A164924 A033579 A294630
KEYWORD
nonn
AUTHOR
Arran Fernandez, Oct 03 2008
EXTENSIONS
a(15)-a(21) from Donovan Johnson, Feb 17 2010
STATUS
approved