

A329532


Numbers k such that Product_{j=1..k} prime(j) + Product_{j=k+1..2*k} prime(j) is prime.


2




OFFSET

1,2


COMMENTS

Based on discussion in primenumbers Yahoo group dated May 12, 2004, with a(9) = 1238 given by Jens Kruse Andersen.
Numbers k such that A002110(k) + A002110(2*k) / A002110(k) is prime.  Daniel Suteu, Nov 22 2019


LINKS

Table of n, a(n) for n=1..10.
Cashogor, Payam Samidoost, David Cleaver, Jens Kruse Andersen, Creating Primes, digest of 9 messages in primenumbers Yahoo group, May 12, 2004. [Cached copy]


PROG

(PARI) for (k=1, 100, if (ispseudoprime(prod(j=1, k, prime(j))+prod(j=k+1, k+k, prime(j))), print1(k, ", ")))


CROSSREFS

Cf. A093429.
Sequence in context: A010345 A233344 A329566 * A265484 A000336 A287433
Adjacent sequences: A329529 A329530 A329531 * A329533 A329534 A329535


KEYWORD

nonn,more,hard


AUTHOR

Hugo Pfoertner, Nov 15 2019


EXTENSIONS

a(10) from Daniel Suteu, Nov 22 2019


STATUS

approved



