A049496 a(n) and a(n)+4^k are primes at least for k=1,2,3,4,5,6.

37, 163, 15667, 53593, 142543, 305407, 607093, 671353, 904663, 1172803, 1233523, 1351837, 1378843, 1389217, 1457857, 1686133, 1842523, 1867783, 2451793, 2668213, 2694157, 2979043, 3095227, 4228723, 4890307, 5535853, 5772097, 5859613, 6404773, 6827503, 6933067

Offset

1,1

Links

Table of n, a(n) for n=1..31.

Formula

A023200 INTERSECT A269259. - R. J. Mathar, Mar 26 2024

Example

37, 37+4=41, 37+16=53, 37+64=101, 37+256=293, 37+1024=1061, 37+4096=4133 are all primes; the smallest such a 7-chain is {37,41,53,101,293,1061,4133}.

Prog

(PARI) isok(n) = isprime(n) && isprime(n+4) && isprime(n+16) && isprime(n+64) && isprime(n+256) && isprime(n+1024) && isprime(n+4096); \\ Michel Marcus, Dec 22 2013

Crossrefs

Cf. A023200, A049492-A049495, A049497-A049500.

Sequence in context: A142909 A269259 A269859 * A049497 A246842 A134219

Adjacent sequences: A049493 A049494 A049495 * A049497 A049498 A049499

Keyword

nonn

Author

Labos Elemer

Extensions

More terms from Michel Marcus, Dec 22 2013

Status

approved