A093864 Consider the least k such that prime(k) > n*composite(k). Sequence gives prime(k).
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
Offset: 1
Keywords
Examples
a(2) = 53 as 53 > 2*26 where 53 and 26 are respectively the 16th prime and composite numbers.
Programs
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PARI
nextcomposite(k)=if(k<3,4,if(isprime(k),k+1,k));
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PARI
p=2;q=4;for(n=1,19, while(p<=n*q,p=nextprime(p+1);q=nextcomposite(q+1));print1(p,","));
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
Comments