A249666 Numbers n such that the sum of n and the largest prime<n (A151799(n)) is prime.

3, 4, 6, 10, 12, 16, 22, 24, 30, 36, 42, 46, 50, 54, 56, 66, 70, 76, 78, 84, 90, 92, 100, 114, 116, 120, 126, 130, 132, 142, 144, 156, 160, 170, 174, 176, 180, 186, 192, 196, 202, 210, 220, 222, 226, 232, 234, 240, 246, 250, 252, 276, 280, 282, 286, 288, 294, 300, 306, 310, 324

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Example

66 is in the sequence because A151799(66)=61, and 66+61=127 is prime.

Mathematica

Select[Range[400], PrimeQ[#+NextPrime[#, -1]]&] (* Harvey P. Dale, Aug 04 2019 *)

Prog

(PARI) {for(i=3, 10^3, k=i+precprime(i-1); if(isprime(k), print1(i, ", ")))}

Crossrefs

Cf. A151799, A249624, A249667, A249676.

Sequence in context: A322165 A057477 A309317 * A113887 A103000 A344516

Adjacent sequences: A249663 A249664 A249665 * A249667 A249668 A249669

Keyword

nonn

Author

Antonio Roldán, Dec 03 2014

Status

approved