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 A084127 Prime factor >= other prime factor of n-th semiprime. 43
 2, 3, 3, 5, 7, 5, 7, 11, 5, 13, 11, 17, 7, 19, 13, 23, 7, 17, 11, 19, 29, 31, 13, 23, 37, 11, 41, 17, 43, 29, 13, 31, 47, 19, 53, 37, 23, 59, 17, 11, 61, 41, 43, 19, 67, 47, 71, 13, 29, 73, 31, 79, 53, 23, 83, 13, 59, 89, 61, 37, 17, 97, 67, 101, 29, 41, 103, 19, 71, 107, 43, 31 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Largest nontrivial divisor of n-th semiprime. [Juri-Stepan Gerasimov, Apr 18 2010] Greater of the prime factors of A001358(n). - Jianing Song, Aug 05 2022 LINKS Zak Seidov, Table of n, a(n) for n = 1..1000 Eric Weisstein's World of Mathematics, Semiprime FORMULA a(n) = A006530(A001358(n)). a(n) = A001358(n)/A020639(A001358(n)). [corrected by Michel Marcus, Jul 18 2020] a(n) = A001358(n)/A084126(n). MATHEMATICA FactorInteger[#][[-1, 1]]& /@ Select[Range[1000], PrimeOmega[#] == 2&] (* Jean-François Alcover, Nov 17 2021 *) PROG (Haskell) a084127 = a006530 . a001358 -- Reinhard Zumkeller, Nov 25 2012 (PARI) lista(nn) = {for (n=2, nn, if (bigomega(n)==2, f = factor(n); print1(f[length(f~), 1], ", ")); ); } \\ Michel Marcus, Jun 05 2013 CROSSREFS Cf. A001358 (the semiprimes), A084126 (lesser of the prime factors of the semiprimes). Cf. A014673, A061299, A068318, A087718, A087794, A089994, A089995, A096932, A106550, A106554, A108542, A126663, A131284, A138510, A138511. Sequence in context: A066072 A239586 A180611 * A089934 A113460 A113470 Adjacent sequences: A084124 A084125 A084126 * A084128 A084129 A084130 KEYWORD nonn AUTHOR Reinhard Zumkeller, May 15 2003 EXTENSIONS Corrected by T. D. Noe, Nov 15 2006 STATUS approved

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Last modified February 26 13:41 EST 2024. Contains 370352 sequences. (Running on oeis4.)