%I A067680
%S A067680 6,21,54,75,441,1071,4191,9315,58311,4197375,7685151,36997695,268460031,
%T A067680 1073790975,17180065791
%N A067680 Numbers n such that sigma(2n+2)=4n.
%Y A067680 Sequence in context: A135454 A069778 A015644 this_sequence A115052 A025203 
               A002817
%Y A067680 Adjacent sequences: A067677 A067678 A067679 this_sequence A067681 A067682 
               A067683
%K A067680 nonn
%O A067680 1,1
%A A067680 Benoit Cloitre (benoit7848c(AT)orange.fr), Feb 04 2002
%E A067680 58311 sent by Benoit Cloitre and Neven Juric (neven.juric(AT)apis-it.hr), 
               May 21 2004
%E A067680 a(10)-a(15) from Donovan Johnson (donovan.johnson(AT)yahoo.com), Jan 
               31 2009