A329102 Numbers k such that both k^2 + 3 and 2^k + 3 are primes.

2, 4, 28, 784

Offset

1,1

Comments

Intersection of A057732 and A049422.

a(5) > 20000. - Tyler NeSmith, May 15 2021

a(5) > 2205444, using A057732. - Michael S. Branicky, Feb 16 2024

Links

Table of n, a(n) for n=1..4.

Crossrefs

Cf. A000040, A057732, A049422, A329103.

Sequence in context: A102692 A292184 A248872 * A126580 A329063 A124687

Adjacent sequences: A329099 A329100 A329101 * A329103 A329104 A329105

Keyword

nonn,hard,more

Author

Alex Ratushnyak, Nov 04 2019

Status

approved