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 A105526 Smallest prime that becomes a product of n distinct primes when a 1 is prepended to it. 2
 3, 5, 113, 1193, 13883, 312311, 10861751, 209551343, 10705778183, 307525001783, 10418232047123, 795076554810539, 17714426958677549, 1015246475642397989, 100019969411961789191, 1728838135940697098327, 165000496158437438012513 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS 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. LINKS PROG (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

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Last modified May 26 02:56 EDT 2020. Contains 334613 sequences. (Running on oeis4.)