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A371619
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a(n) is the least integer m such that p#*m - 1 is prime for all primes p <= prime(n).
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0
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2, 2, 2, 2, 9, 9, 9, 224719, 384427, 16114470, 259959472, 13543584514, 100318016379, 100318016379
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OFFSET
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1,1
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LINKS
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PROG
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(PARI) isok(m, n) = for(i=1, n, my(P = vecprod(primes(i))); if (! isprime(P*m-1), return(0)); ); return(1);
a(n) = my(m=1); while (!isok(m, n), m++); m;
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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STATUS
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approved
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