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Numbers n such that sigma(n)=3*reversal(n).
2

%I #10 Oct 02 2013 15:12:50

%S 41,291552,692133,2946762,8231796,21732508611,27892659612

%N Numbers n such that sigma(n)=3*reversal(n).

%C No more terms through 10^9. - _Ryan Propper_, Jan 08 2007

%C a(8) > 10^12. - _Giovanni Resta_, Oct 28 2012

%t Do[If[DivisorSigma[1, n] == 3*FromDigits[Reverse[IntegerDigits[n]]], Print[n]], {n, 20000000}]

%Y Cf. A069216, A105324, A114928.

%K base,more,nonn

%O 1,1

%A _Farideh Firoozbakht_, Jan 28 2006

%E a(6)-a(7) from _Donovan Johnson_, Dec 21 2008