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A174229 Natural numbers n such that the concatenation n^3//1331, i.e., a cube and 11^3, is a prime number. 1

%I

%S 2,6,8,14,21,38,39,51,54,65,68,78,80,93,104,107,114,117,119,125,135,

%T 137,146,147,152,153,158,159,167,186,206,225,243,246,248,257,258,269,

%U 270,272,278,284,290,291,306,311,317,321,323,324,369,372,387,390,399,404,410,414,425

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

%C See comments and references for A174213.

%e 2^3 = 8, 81331 = prime(7958) => a(1) = 2;

%e 6^3 = 216, 2161331 = prime(160048) => a(2) = 6.

%o (PARI) isok(n) = isprime(eval(concat(Str(n^3), Str(1331)))); \\ _Michel Marcus_, Jul 20 2017

%Y Cf. A168327, A168417, A173836, A174213.

%K base,nonn

%O 1,1

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

%E More terms from _Michel Marcus_, Jul 20 2017

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Last modified May 18 15:25 EDT 2021. Contains 343995 sequences. (Running on oeis4.)