A145907 Primes p such that p + ceiling(sqrt(p)) is also prime.

3, 13, 31, 53, 59, 97, 127, 137, 139, 179, 241, 293, 313, 389, 457, 547, 563, 569, 647, 733, 769, 853, 857, 877, 881, 977, 1019, 1117, 1129, 1153, 1283, 1291, 1409, 1433, 1531, 1543, 1567, 1579, 1597, 1699, 1741, 1747, 1759, 1889, 1907, 2053, 2083, 2221

Offset

1,1

Links

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Example

For p = 13; 13 + ceiling(sqrt(13)) = 17, which is prime.

Mathematica

Select[Prime[Range[400]], PrimeQ[#+Ceiling[Sqrt[#]]]&] (* Harvey P. Dale, Aug 17 2019 *)

Prog

(PARI) isok(n) = isprime(n) && isprime(n + sqrtint(n) + 1); \\ Michel Marcus, Aug 15 2013

Crossrefs

Cf. A086085, A145908.

Sequence in context: A171517 A179026 A179027 * A054554 A051939 A257764

Adjacent sequences: A145904 A145905 A145906 * A145908 A145909 A145910

Keyword

nonn

Author

Kyle D. Balliet, Oct 24 2008, Nov 06 2008

Extensions

More terms from R. J. Mathar, Oct 31 2008

Status

approved