%I A051027
%S A051027 1,4,7,8,12,28,15,24,14,39,28,56,24,60,60,32,39,56,42,96,63,91,60,168,
%T A051027 32,96,90,120,72,195,63,104,124,120,124,112,60,168,120,234,96,252,84,
%U A051027 224,168,195,124,224,80,128,195,171,120,360,195,360,186,234,168,480,96
%N A051027 a(n) = sigma(sigma(n)) = sum of the divisors of the sum of the divisors 
               of n.
%H A051027 T. D. Noe, <a href="b051027.txt">Table of n, a(n) for n=1..5000</a>
%p A051027 with(numtheory): [seq(sigma(sigma(n)), n=1..100)];
%t A051027 lst={};Do[AppendTo[lst,DivisorSigma[1,DivisorSigma[1,n]]],{n,5!}];lst 
               [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Mar 11 2009]
%Y A051027 Cf. A000203.
%Y A051027 Sequence in context: A070286 A047536 A093494 this_sequence A073435 A086987 
               A051219
%Y A051027 Adjacent sequences: A051024 A051025 A051026 this_sequence A051028 A051029 
               A051030
%K A051027 easy,nice,nonn
%O A051027 1,2
%A A051027 Judson D. Neer (judson(AT)poboxes.com)