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 A084127 Prime factor >= other prime factor of n-th semiprime. 41
 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] 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). 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. 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 May 14 11:57 EDT 2021. Contains 343882 sequences. (Running on oeis4.)