This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A174260 #3 Jun 22 2013 11:57:58 %S A174260 23,29,53,101,113,239,281,311,347,353,389,401,431,617,641,647,743,797, %T A174260 821,827,863,911,941,1049,1283,1319,1373,1439,1481,1487,1493,1511, %U A174260 1583,1613,1667,1709,1721,1733,1823,1949 %N A174260 Prime numbers p such that the concatenation p//1331 is a prime number. %C A174260 Necessarily (as sod(1331) = 3 * 2 + 2): p = 6 * k - 1 %C A174260 See comments and references for A174213 %e A174260 231331 = prime(20545) => p(1) = 23 = prime(9) %e A174260 291331 = prime(25334) => p(2) = 29 = prime(10) %t A174260 Select[Prime[Range[300]],PrimeQ[1331+10000#]&] (* _Harvey P. Dale_, Jun 22 2013 *) %Y A174260 A168327, A168417, A173836, A174213 %K A174260 base,nonn %O A174260 1,1 %A A174260 Eva-Maria Zschorn (e-m.zschorn(AT)zaschendorf.km3.de), Mar 14 2010