A049498 a(n) and a(n)+4^k are primes at least for k=1,2,3,4,5,6,7,8.

163, 15667, 607093, 671353, 1457857, 5772097, 9139453, 11170933, 13243063, 18116473, 19433863, 21960577, 32380177, 52896517, 115831753, 154146133, 165609217, 191489677, 361241743, 394845313, 518774953, 613615423, 705676717, 742403797, 786242293, 945170293

Offset

1,1

Links

Table of n, a(n) for n=1..26.

Example

163, 163+4 = 167, 163+16 = 179, 163+64 = 227, 163+256 = 419, 163+1024 = 1187, 163+4096 = 4259, 163+16384 = 16547, 163+65536 = 65699 are all primes; the smallest such a 9-chain of primes is {163, 167, 178, 227, 419, 1187, 4259, 16547, 65699}

Mathematica

  With[{c=4^Range[8]}, Select[Prime[Range[500000]], And@@PrimeQ[#+c]&]] (* Harvey P. Dale, May 22 2012 *)

Crossrefs

Cf. A023200, A049492-A049497, A049499-A049500.

Sequence in context: A134160 A219127 A270203 * A217456 A138932 A217963

Adjacent sequences: A049495 A049496 A049497 * A049499 A049500 A049501

Keyword

nonn

Author

Labos Elemer

Extensions

More terms from Michel Marcus, Dec 22 2013

Status

approved