Search: id:A136106
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%I A136106
%S A136106 2,5,103,1867,491851,17681491,35565206671
%N A136106 a(n) = smallest prime p such that in the sequence of n numbers p, p+1, 
               p+2, ..., p+n-1, the i-th terms is the product of i distinct primes, 
               for i = 1, ..., n.
%F A136106 a(n) >= A086560(n). - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Feb 
               05 2008
%e A136106 a(4)=1867 because it begins with the prime 1867 (considered as just one 
               divisor) followed by 1868 with two prime factors, 2 and 467; then 
               1869 with three prime factors, 3, 7, 89; then 1870 with four prime 
               factors, 2, 5, 11,17.
%o A136106 (PARI) /* a brute force program */ a136106(st,ed,ct)={ forprime(x=st,
               ed, if ((x%6)!=1,next); goodFlag = 1; c = 1; while(goodFlag, if (!(c%2) 
               && isprime(x+c), goodFlag=0, v = factor(x+c); if (length(v[,2]) == 
               c+1, c+=1; if (c > ct,print("Level = ",c," at ",x+c-1,"=",v); ct+=1), 
               goodFlag = 0 ) ) ) ); } -Fred Schneider (frederick.william.schneider(AT)gmail.com), 
               Dec 18 2007
%Y A136106 Cf. A072875.
%Y A136106 Sequence in context: A066618 A027720 A132482 this_sequence A122696 A023263 
               A070855
%Y A136106 Adjacent sequences: A136103 A136104 A136105 this_sequence A136107 A136108 
               A136109
%K A136106 easy,more,nonn
%O A136106 1,1
%A A136106 Enoch Haga (Enokh(AT)comcast.net), Dec 14 2007
%E A136106 Edited by N. J. A. Sloane (njas(AT)research.att.com), Dec 23 2007
%E A136106 2 more terms from Fred Schneider (frederick.william.schneider(AT)gmail.com), 
               Dec 18 2007
%E A136106 a(7) from Donovan Johnson (donovan.johnson(AT)yahoo.com), Sep 19 2009

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