A378906 Primes p1 such that (p4 - p3) < (p2 - p1), where [p1, p2] and [p3, p4] are pairs of consecutive primes and p3 < p1*p2 < p4.

211, 773, 887, 1069, 1237, 1327, 1511, 1759, 1913, 2069, 2503, 2593, 2819, 2861, 2971, 3089, 3271, 3833, 4297, 4397, 4523, 4831, 4909, 5119, 5261, 5281, 5351, 5591, 5939, 5953, 5987, 6011, 6287, 6427, 6619, 6871, 7369, 7393, 7649, 7759, 7793, 7963, 8543, 8647, 8783, 8971

Offset

1,1

Links

Hugo Pfoertner, Table of n, a(n) for n = 1..10000

User robert44444uk and others, Does this series tend to infinity or to a constant? Thread in mersenneforum.org, started 2024-10-21.

Prog

(PARI) a378906(upto) = my(p1=3); forprime(p2=5, upto, my(P=p1*p2, p3=precprime(P), p4=nextprime(P)); if(p2-p1 > p4-p3, print1(p1, ", ")); p1=p2);
a378906(9000)

Crossrefs

Cf. A001223, A006094.

Sequence in context: A142761 A308798 A342508 * A104299 A032632 A241959

Adjacent sequences: A378903 A378904 A378905 * A378907 A378908 A378909

Keyword

nonn,easy

Author

Hugo Pfoertner, Dec 18 2024

Status

approved