A379380 Prime numbers p such that (2*p)# - p# + 1 is prime, where p# = A034386(p).

1, 2, 5, 17, 103, 113, 193, 277, 3671, 9419, 12671, 30809, 34439, 83833, 89227, 106103, 107101, 175303, 398903

Offset

1,2

Links

Table of n, a(n) for n=1..19.

Example

For p = 17: the product of the primes from 2 to p*2 is 2*3*5*7*11*13*17*19*23*29*31 = 200560490130, and the product of the primes from 2 to p is 2*3*5*7*11*13*17 = 510510.  200560490130 - 510510 + 1 = 200559979621, a prime number.

Crossrefs

Cf. A034386, A237443.

Sequence in context: A203006 A143878 A081546 * A103511 A254132 A161609

Adjacent sequences: A379377 A379378 A379379 * A379381 A379382 A379383

Keyword

nonn,hard,more

Author

Kellen Shenton, Dec 21 2024

Status

approved