A168487 - OEIS

%I #6 Nov 21 2013 12:49:44

%S 127,827,6427,12527,34327,219727,491327,1562527,2438927,3276827,

%T 8518427,16637527,22698127,43897627,45653327,51200027,77868827,

%U 119101627,129502927,140492827,156089627,177156127,190662427,251545627,257135327

%N Primes of the form 100n^3 + 27.

%C (1) These primes all with the end digits 2 and 7 are concatenations of two CUBIC numbers: "n^3 3^3".

%C (2) It is conjectured that sequence is infinite.

%D Harold Davenport, Multiplicative Number Theory, Springer-Verlag New-York 1980

%D Leonard E. Dickson: History of the Theory of numbers, vol. I, Dover Publications 2005

%D Friedhelm Padberg, Elementare Zahlentheorie, Spektrum Akademischer Verlag, 2. Auflage 1991

%t Select[100Range[140]^3+27,PrimeQ] (* _Harvey P. Dale_, Aug 22 2011 *)

%Y A167535 Concatenation of two square numbers which give a prime

%Y A168147 Primes of the form p = 1 + 10*n^3 for a natural number n

%Y A168327 Primes of concatenated form p = "1 n^3"

%K nonn

%O 1,1

%A Eva-Maria Zschorn (e-m.zschorn(AT)zaschendorf.km3.de), Nov 27 2009

%E Edited by _Charles R Greathouse IV_, Apr 24 2010