This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A233467 #13 Mar 15 2014 17:56:43 %S A233467 14,134,164,1333334,133333334,929247534,1333333334,133333333334 %N A233467 Numbers n such that sigma(n) = reversal(3n). %C A233467 If m is a natural number and p=(2*10^m+1)/3 is prime then 2*p is in the sequence (see A096507). %C A233467 a(9) > 10^12. - _Giovanni Resta_, Mar 15 2014 %e A233467 sigma(14)=24=reversal(42)=reversal(3*14). %t A233467 rev[n_] := FromDigits@ Reverse@ IntegerDigits@n; Select[Range[2*10^6], DivisorSigma[1, #] == rev[3*#] &] (* _Giovanni Resta_, Mar 15 2014 *) %Y A233467 Cf. A000203, A004086, A233465. %K A233467 nonn,base,more %O A233467 1,1 %A A233467 _Farideh Firoozbakht_, Mar 14 2014 %E A233467 a(6)-a(8) from _Giovanni Resta_, Mar 15 2014