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Search: id:A105526
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%I A105526
%S A105526 3,5,113,1193,13883,312311,10861751,209551343,10705778183,307525001783,
%T A105526 10418232047123,795076554810539,17714426958677549,1015246475642397989,
%U A105526 100019969411961789191,1728838135940697098327,165000496158437438012513
%N A105526 Smallest prime that becomes a product of n distinct primes when a 1 is 
               prepended to it.
%C A105526 We have a(2)=5 because 5 is the smallest prime (ahead of 11,19,19,23,
               29,...) that is a product of two distinct primes when a 1 is prepended.
%o A105526 (PARI) {len10(n) = ceil(log(n+1)/log(10))} {r(n,p,d)=local(q);if(d==0,
               k=n-10^(len10(n)-1);if(len10(k)==len10(n)-1 && isprime(k),m=n);return);
               q=nextprime(p+1);while(n*q^d<m,r(n*q,q,d-1);q=nextprime(q+1))} {A105526(d) 
               = M=3^d;while(1,m=M;r(1,2,d);if(m!=M,return(m%10^(len10(m)-1)));M*=2)} 
               (Alekseyev)
%Y A105526 Cf. A105525.
%Y A105526 Sequence in context: A054266 A054268 A153137 this_sequence A070743 A103993 
               A088269
%Y A105526 Adjacent sequences: A105523 A105524 A105525 this_sequence A105527 A105528 
               A105529
%K A105526 nonn,base
%O A105526 1,1
%A A105526 Lekraj Beedassy (blekraj(AT)yahoo.com), Apr 11 2005
%E A105526 a(5)-a(8) from Ray Chandler (rayjchandler(AT)sbcglobal.net), Apr 21 2005
%E A105526 More terms from Max Alekseyev (maxale(AT)gmail.com), Apr 28 2005

    
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Last modified December 10 00:48 EST 2009. Contains 170565 sequences.


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