A174229 -id:A174229 - cp's OEIS frontend

A174409 Prime numbers p such that the concatenation p^3//1331 is a prime number.

2, 107, 137, 167, 257, 269, 311, 317, 557, 593, 761, 773, 809, 911, 1103, 1151, 1283, 1289, 1481, 1487, 1559, 1709, 1787, 1931, 2111, 2141, 2243, 2339, 2357, 2657, 2687, 2777, 2909, 3137, 3209, 3251, 3359, 3371, 3389, 3449

Offset: 1

Eva-Maria Zschorn (e-m.zschorn(AT)zaschendorf.km3.de), Mar 19 2010

See comments at A174213.
p^3//1331 is the concatenation of the cubes of two primes.
With the exception of a(1)=2, each term is necessarily of the form 6*k-1.

			The first prime is 2; 2^3 = 8, and 81331 = prime(7958), so a(1)=2.
The smallest prime p > 2 such that p^3//1331 yields a prime is p=107: 107^3 = 1225043, and 12250431331 = prime(552342812), so a(2)=107.

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

Cf. A168327, A168417, A173836, A174213, A174260, A174229, A174355.

[p: p in PrimesUpTo(5000) | IsPrime(Seqint(Intseq(1331) cat Intseq(p^3)))]; // Vincenzo Librandi, Mar 05 2018

Select[Prime[Range[500]],PrimeQ[10000#^3+1331]&] (* Harvey P. Dale, May 30 2017 *)

cp's OEIS Frontend

A174409 Prime numbers p such that the concatenation p^3//1331 is a prime number.

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