Search: id:A111012 Results 1-1 of 1 results found. %I A111012 %S A111012 2,101,1998541,3366950329,803128907400221,16099934940822131461, %T A111012 2279520764596558292681,6469963748546758449049574741, %U A111012 10900112859698650263468714158129 %N A111012 Primes in A002532. %C A111012 Starting with the fraction 1/1, generate the sequence of fractions A002533(i)/ A002532(i) according to %C A111012 the rule: "add top and bottom to get the new bottom, add top and 6 times bottom to get the new top." %C A111012 The prime denominators of these fractions are listed here, at locations i= 2, 5, 13, 19, 29, 37,.. %C A111012 41, 53, 59, .... equalling prime(1), prime(26), prime(148838), .. %C A111012 Is there an infinity of primes in this sequence? %D A111012 Prime Obsession, John Derbyshire, Joseph Henry Press, April 2004, p 16. %F A111012 A002532 INTERSECT A000040. %o A111012 (PARI) primenum(n,k,typ) = \\ k=mult,typ=1 num,2 denom. output prime num or denom. %o A111012 { local(a,b,x,tmp,v); a=1;b=1; %o A111012 for(x=1,n, tmp=b; b=a+b; a=k*tmp+a; if(typ==1,v=a,v=b); if(isprime(v), print1(v","); ) ); %o A111012 print(); print(a/b+.) } %Y A111012 Sequence in context: A035325 A028989 A113575 this_sequence A157066 A055693 A106299 %Y A111012 Adjacent sequences: A111009 A111010 A111011 this_sequence A111013 A111014 A111015 %K A111012 easy,nonn %O A111012 1,1 %A A111012 Cino Hilliard (hillcino368(AT)hotmail.com), Oct 02 2005 %E A111012 Simplified the definition, listed some A002532 indices - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Sep 16 2009 Search completed in 0.001 seconds