%I A110929
%S A110929 50,850,1300,2210,6100,8500,14500,18100,22100,22100,22100,24650,26500,
%T A110929 32550,42500,42100,48100,48100,48100,68500,68900,84100,92500,103700,
%U A110929 110500,110500,110500,140500,158600,174100,201110,186100,221000,224500
%N A110929 The common value of sigma_2 for square-amicable numbers, sigma_2(m)=sigma_2(n), 
               m<n.
%F A110929 sigma_2(m)=sigma_2(n), m<n
%e A110929 sigma_2(30)=1^1+2^2+3^2+5^2+6^2+10^2+15^2+30^2=1300 and sigma_2(35)=1^2+5^2+7^2+35^2=1300.
%p A110929 with(numtheory); sigmap := proc(p,n) convert(map(proc(z) z^p end, divisors(n)),
               `+`) end; SA2:=[]: for z from 1 to 1 do for m to 1500 do M:=sigmap(2,
               m); for n from m+1 to 1500 do N:=sigmap(2,n); if N=M then SA2:=[op(SA2),
               [m,n,N]] fi od od od; SA2; select(proc(z) z[1]<=1000 end, SA2); #just 
               to shorten it a bit
%Y A110929 Cf. A001157, A002025, A002046, A063990.
%Y A110929 Sequence in context: A160287 A104672 A086027 this_sequence A101929 A006360 
               A112890
%Y A110929 Adjacent sequences: A110926 A110927 A110928 this_sequence A110930 A110931 
               A110932
%K A110929 nonn
%O A110929 1,1
%A A110929 Walter A. Kehowski (wkehowski(AT)cox.net), Sep 23 2005