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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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Harvey P. Dale, Table of n, a(n) for n = 1..1000 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 Adjacent sequences: A176567 A176568 A176569 * A176571 A176572 A176573 KEYWORD nonn AUTHOR Juri-Stepan Gerasimov, Apr 20 2010 EXTENSIONS Entries checked by R. J. Mathar, Apr 27 2010 STATUS approved

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Last modified May 29 08:13 EDT 2023. Contains 363029 sequences. (Running on oeis4.)