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%I #4 Jun 09 2015 16:55:26
%S 3,17,53,83,107,227,251,269,293,347,383,431,443,521,587,599,641,647,
%T 683,719,761,773,821,857,929,1031,1097,1217,1223,1301,1367,1409,1433,
%U 1451,1619,1637,1709,1787,1973,2081,2087,2129,2399,2477,2591,2633,2657,2693
%N Primes p which give primes when 1331 = 11^3 is prefixed (see A173579).
%C N = 1331 = 11^3, p k-digit prime, to check if q = N * 10^k + p is prime
%C With exception of 3 necessarily p of form 3k+2, as sod(1331 = 8)
%D K. Haase, P. Mauksch: Spass mit Mathe, Urania-Verlag Leipzig, Verlag Dausien Hanau, 2. Auflage 1985
%D Helmut Kracke, Mathe-musische Knobelisken, Duemmler Bonn, 2. Auflage 1983
%H Harvey P. Dale, <a href="/A173733/b173733.txt">Table of n, a(n) for n = 1..1000</a>
%e 13313 = prime(1581) => a(1) = prime(2) = 3
%e 133117 = prime(12425) => a(2) = prime(7) = 17
%e 133153 = prime(12427) => a(3) = prime(16) = 53
%e 13311217 = prime(868166) => a(28) = prime(199) = 1217
%e 13311223 = prime(868167) => a(29) = prime(200) = 1223
%e Note: two consecutive primes P = prime(n), Q = prime(n+1) yield consecutive prime concatenations "N P" = prime(m) and "N Q" = prime(m+1)
%t Select[Prime[Range[400]],PrimeQ[FromDigits[Join[{1,3,3,1}, IntegerDigits[ #]]]]&] (* _Harvey P. Dale_, Jun 09 2015 *)
%Y Cf. A102006, A167535, A168147, A168219, A168274, A173579
%K nonn,base,less
%O 1,1
%A Eva-Maria Zschorn (e-m.zschorn(AT)zaschendorf.km3.de), Feb 23 2010
%E Edited and extended by _Charles R Greathouse IV_, Apr 24 2010
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