A168006 - OEIS

%I #9 Jul 05 2016 02:48:23

%S 37,61,71,163,173,193,367,397,479,499,521,541,571,601,631,641,661,691,

%T 701,751,761,811,821,881,911,941,971,991,1523,1543,1553,1583,1613,

%U 1663,1693,1723,1733,1753,1783,1823,1873,1913,1933,1973,1993,3517,3527,3547

%N Primes n with property that first digit of 2*n = last digit of n.

%C Or, primes in A167994.

%H G. C. Greubel, <a href="/A168006/b168006.txt">Table of n, a(n) for n = 1..1000</a>

%e 2*37=74, 2*61=122.

%t Select[Prime[Range[800]],First[IntegerDigits[2#]]==Last[ IntegerDigits[#]]&] (* _Harvey P. Dale_, May 27 2011 *)

%Y Cf. A167994.

%K base,nonn

%O 1,1

%A _Zak Seidov_, Nov 16 2009