%I A019286
%S A019286 168,10752,331520,691200,1556480,1612800,106151936
%N A019286 Let sigma_m (n) be result of applying sum-of-divisors function m times 
               to n; call n (m,k)-perfect if sigma_m (n) = k*n; sequence gives the 
               (2,9)-perfect numbers.
%C A019286 See also the Cohen-te Reile links under A019276.
%D A019286 Graeme L. Cohen and Herman J. J. te Riele, Iterating the sum-of-divisors 
               function, Experimental Mathematics, 5 (1996), pp. 93-100.
%H A019286 Experimental Mathematics, <a href="http://www.expmath.org/">Home Page</
               a>
%Y A019286 Sequence in context: A011785 A003800 A006363 this_sequence A064767 A115222 
               A035827
%Y A019286 Adjacent sequences: A019283 A019284 A019285 this_sequence A019287 A019288 
               A019289
%K A019286 nonn
%O A019286 1,1
%A A019286 N. J. A. Sloane (njas(AT)research.att.com).