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A365710
a(n) = second smallest distinct prime factor of A126706(n).
1
3, 3, 5, 3, 7, 3, 5, 11, 5, 3, 5, 13, 3, 7, 3, 7, 17, 3, 5, 19, 5, 3, 11, 3, 23, 3, 7, 11, 5, 13, 3, 7, 29, 13, 3, 31, 3, 3, 5, 17, 5, 3, 7, 37, 3, 19, 17, 3, 5, 3, 41, 3, 19, 43, 7, 11, 3, 23, 47, 7, 3, 7, 3, 5, 3, 23, 13, 53, 3, 5, 7, 5, 3, 29, 3, 59, 3, 11
OFFSET
1,1
COMMENTS
Since omega(A126706(n)) = A001221(A126706(n)) > 1, and since A126706 is infinite, a(n) exists for all n.
FORMULA
a(n) = A119288(A126706(n)) > 2.
EXAMPLE
Let b(n) = A126706(n).
a(1) = 3 since b(1) = 12 = 2^2 * 3.
a(2) = 3 since b(2) = 18 = 2 * 3^2.
a(3) = 5 since b(3) = 20 = 2^2 * 5, etc.
MATHEMATICA
FactorInteger[#][[2, 1]] & /@ Select[Range[250], PrimeOmega[#] > PrimeNu[#] > 1 &]
CROSSREFS
Sequence in context: A163167 A243729 A200810 * A114003 A219792 A029622
KEYWORD
nonn,easy
AUTHOR
Michael De Vlieger, Jan 05 2024
STATUS
approved