%I #10 Jul 14 2013 09:15:06
%S 6,8,10,14,27,39,51,57,745,755,7091,268243,439681,3271489,33559819,
%T 74138989,80194627,179405777,1131818923,1170569879,1324475807,
%U 1324478657,51086967247,72229691441,72229691533,72229691993,72229693511
%N Numbers n such that sigma(n) = n-th composite number.
%o (PARI) isok(n) = (sigma(n) == A002808(n)) \\ (see script there). _Michel Marcus_, Jul 14 2013
%Y Cf. A002808, A000203.
%K nonn
%O 1,1
%A _Naohiro Nomoto_
%E a(15)-a(22) from _Donovan Johnson_, Apr 03 2008
%E a(23)-a(27) from _Donovan Johnson_, Oct 24 2010