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A176570
a(n)=n-th semiprime if n-th semiprime odd and n-th semiprime/2 if n-th semiprime even.
1
2, 3, 9, 5, 7, 15, 21, 11, 25, 13, 33, 17, 35, 19, 39, 23, 49, 51, 55, 57, 29, 31, 65, 69, 37, 77, 41, 85, 43, 87, 91, 93, 47, 95, 53, 111, 115, 59, 119, 121, 61, 123, 129, 133, 67, 141, 71, 143, 145, 73, 155, 79, 159, 161, 83, 169, 177, 89, 183, 185, 187, 97, 201, 101, 203
OFFSET
1,1
LINKS
MATHEMATICA
If[EvenQ[#], #/2, #]&/@Select[Range[300], PrimeOmega[#]==2&] (* Harvey P. Dale, Nov 01 2019 *)
CROSSREFS
Cf. A001358.
Sequence in context: A065631 A222244 A325645 * A269559 A083173 A120725
KEYWORD
nonn
AUTHOR
EXTENSIONS
Entries checked by R. J. Mathar, Apr 27 2010
STATUS
approved