A174229 Natural numbers n such that the concatenation n^3//1331, i.e., a cube and 11^3, is a prime number.

2, 6, 8, 14, 21, 38, 39, 51, 54, 65, 68, 78, 80, 93, 104, 107, 114, 117, 119, 125, 135, 137, 146, 147, 152, 153, 158, 159, 167, 186, 206, 225, 243, 246, 248, 257, 258, 269, 270, 272, 278, 284, 290, 291, 306, 311, 317, 321, 323, 324, 369, 372, 387, 390, 399, 404, 410, 414, 425

Offset

1,1

Comments

See comments and references for A174213.

Links

Table of n, a(n) for n=1..59.

Example

2^3 = 8, 81331 = prime(7958) => a(1) = 2;
6^3 = 216, 2161331 = prime(160048) => a(2) = 6.

Prog

(PARI) isok(n) = isprime(eval(concat(Str(n^3), Str(1331)))); \\ Michel Marcus, Jul 20 2017

Crossrefs

Cf. A168327, A168417, A173836, A174213.

Sequence in context: A270050 A137831 A117588 * A187217 A022112 A107019

Adjacent sequences: A174226 A174227 A174228 * A174230 A174231 A174232

Keyword

base,nonn

Author

Eva-Maria Zschorn (e-m.zschorn(AT)zaschendorf.km3.de), Mar 13 2010

Extensions

More terms from Michel Marcus, Jul 20 2017

Status

approved