%I A131645
%S A131645 6661,16661,26669,46663,56663,66601,66617,66629,66643,66653,66683,66697,
%T A131645 76667,96661,96667,106661,106663,106669,116663,146669,166601,166603,
%U A131645 166609,166613,166619,166627,166631,166643,166657,166667,166669,166679
%N A131645 Beastly primes (primes containing 666 as a substring).
%C A131645 Asymptotic density n/log(n), since almost all primes are of this form.
%H A131645 Charles R Greathouse IV and Harry J. Smith, <a href="b131645.txt">Table 
               of n, a(n) for n=1..20000</a>
%t A131645 Select[Range[300000], StringFreeQ[ToString[ # ], "666"] == False && PrimeQ[ 
               # ] &]
%t A131645 Select[Prime[Range[300000]],!StringFreeQ[ToString[ # ],"666"]&] - from 
               Zak Seidov, Jan 09 2009
%o A131645 (PARI) digitsIn(x) = 1 + log(x)\log(10) { allocatemem(932245000); default(primelimit, 
               4294965247); m=1; forprime (p=6660, 68466670, d=digitsIn(p); for 
               (i=1, d-3, t=10^i; u=p\t; x=u-(u\1000)*1000; if (x==666, print(m, 
               " ", p); write("b131645.txt", m, " ", p); m=m+1; break;); ) ) } [From 
               Harry J. Smith (hjsmithh(AT)sbcglobal.net), Jan 11 2009]
%Y A131645 Sequence in context: A043634 A060792 A119519 this_sequence A015310 A043516 
               A046410
%Y A131645 Adjacent sequences: A131642 A131643 A131644 this_sequence A131646 A131647 
               A131648
%K A131645 base,nonn
%O A131645 1,1
%A A131645 Tanya Khovanova (tanyakh(AT)yahoo.com), Sep 08 2007