A371619 a(n) is the least integer m such that p#*m - 1 is prime for all primes p <= prime(n).

2, 2, 2, 2, 9, 9, 9, 224719, 384427, 16114470, 259959472, 13543584514, 100318016379, 100318016379

Offset

1,1

Links

Table of n, a(n) for n=1..14.

Martin Raab, A prime number "Game of Life": can floor(y*p#) be prime for all p>=2?, arXiv:2403.17949 [math.GM], 2024.

Prog

(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;

Crossrefs

Cf. A002110.

Sequence in context: A353392 A360310 A085056 * A265447 A156538 A249768

Adjacent sequences: A371616 A371617 A371618 * A371620 A371621 A371622

Keyword

nonn,more

Author

Michel Marcus, Mar 29 2024

Status

approved