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%I #8 Sep 11 2015 14:45:58
%S 6,741,973,4056,4296,41642,49222,425822,457042,498906,831805,998462,
%T 20671542,41673714,73687923,4158499614,54809993252,67820167555
%N Numbers n such that if m = reverse(sigma(n)-n) then n = reverse(sigma(m)-m).
%C Fixed points of the transform n -> reverse(sigma(reverse(sigma(n)-n))- reverse(sigma(n)-n)).
%C a(19) > 10^11. - _Hiroaki Yamanouchi_, Sep 11 2015
%e sigma(741)-741 = 379 and reverse(379)=973;
%e sigma(973)-973 = 147 and reverse(147)=741;
%p with(numtheory): T:=proc(w) local x,y,z; x:=0; y:=w;
%p for z from 1 to ilog10(w)+1 do x:=10*x+(y mod 10); y:=trunc(y/10); od; x; end:
%p P:=proc(q) local a,b,k,n;
%p for n from 1 to q do if n=T(sigma(T(sigma(n)-n))-T(sigma(n)-n)) then
%p print(n); fi; od; end: P(10^12);
%Y Cf. A000203.
%K nonn,base,more
%O 1,1
%A _Paolo P. Lava_, Dec 09 2014
%E a(13)-a(18) from _Hiroaki Yamanouchi_, Sep 11 2015
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