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 A093864 Consider the least k such that prime(k) > n*composite(k). Sequence gives prime(k). 1
 11, 53, 173, 521, 1523, 4327, 11579, 31469, 85411, 229547, 614477, 1640461, 4393369, 11806297, 31656553, 84979847, 228346229, 614582509, 1654328267, 4457160931, 12016414601, 32419200013, 87508870037, 236325429049, 638490906857, 1725782162981, 4666340800001 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(n) = prime(A073459(n)). LINKS EXAMPLE a(2) = 53 as 53 > 2*26 where 53 and 26 are respectively the 16th prime and composite numbers. PROG (PARI) nextcomposite(k)=if(k<3, 4, if(isprime(k), k+1, k)); (PARI) p=2; q=4; for(n=1, 19, while(p<=n*q, p=nextprime(p+1); q=nextcomposite(q+1)); print1(p, ", ")); CROSSREFS Cf. A002808, A000040, A073459, A125075. Sequence in context: A141893 A093198 A207361 * A139967 A227965 A196468 Adjacent sequences: A093861 A093862 A093863 * A093865 A093866 A093867 KEYWORD nonn AUTHOR Amarnath Murthy, Apr 19 2004 EXTENSIONS Terms a(4) to a(19) and PARI code from Klaus Brockhaus, Apr 26 2004 Terms a(20) to a(23) from Klaus Brockhaus, Nov 19 2006 More terms from David Wasserman, Apr 20 2007 STATUS approved

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Last modified March 29 18:41 EDT 2023. Contains 361599 sequences. (Running on oeis4.)