%I A140078
%S A140078 7314,8294,8645,9009,10659,11570,11780,11934,13299,13629,13845,14420,
%T A140078 15105,15554,16554,16835,17204,17390,17654,17765,18095,18290,18444,
%U A140078 18920,19005,19019,19095,19227,20349,20405,20769,21164,21489,21735
%N A140078 Numbers n such that n and n+1 have 4 distinct prime factors.
%C A140078 For numbers n such that n and n+1 have k distinct prime factors see:
%C A140078 k=2 A074851
%C A140078 k=3 A140077
%C A140078 k=4 A140078
%C A140078 k=5 A140079
%H A140078 D. A. Goldston, S. W. Graham, J. Pintz and C. Y. Yildirim., <a href="http:/
               /front.math.ucdavis.edu/0803.2636">Small gaps between almost primes, 
               the parity problem and some conjectures of Erdos on consecutive integers</
               a>.
%t A140078 a = {}; Do[If[Length[FactorInteger[n]] == 4 && Length[FactorInteger[n 
               + 1]] == 4, AppendTo[a, n]], {n, 1, 100000}]; a (*Artur Jasinski*)
%Y A140078 Cf. A074851, A140077, A140079 .
%Y A140078 Sequence in context: A152502 A031799 A116248 this_sequence A117799 A097696 
               A128478
%Y A140078 Adjacent sequences: A140075 A140076 A140077 this_sequence A140079 A140080 
               A140081
%K A140078 nonn
%O A140078 1,1
%A A140078 Artur Jasinski (grafix(AT)csl.pl), May 07 2008