OFFSET
1,1
COMMENTS
These are the primes among the beastly numbers A051003.
There are several other definitions of beastly primes (see cross-references).
Asymptotic density n/log(n), since almost all primes are of this form.
LINKS
Charles R Greathouse IV and Harry J. Smith, Table of n, a(n) for n = 1..20000
Tony Padilla and Brady Haran, The Most Evil Number, Numberphile video (2018)
FORMULA
a(n) ~ n log n. - Charles R Greathouse IV, Oct 13 2015
MATHEMATICA
Select[Range[300000], StringFreeQ[ToString[ # ], "666"] == False && PrimeQ[ # ] &]
Select[Prime[Range[300000]], !StringFreeQ[ToString[ # ], "666"]&] (* Zak Seidov, Jan 09 2009 *)
PROG
(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++; break))) \\ Harry J. Smith, Jan 11 2009
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Tanya Khovanova, Sep 08 2007
EXTENSIONS
Definition corrected by Arkadiusz Wesolowski, Feb 12 2011
Edited by N. J. A. Sloane, Feb 12 2011
STATUS
approved