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A145907 Primes p such that p + ceiling(sqrt(p)) is also prime. 2
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified October 19 04:40 EDT 2019. Contains 328211 sequences. (Running on oeis4.)