Search: id:A072234
Results 1-1 of 1 results found.

%I A072234
%S A072234 6,498906,20671542,41673714,73687923
%N A072234 Numbers n such that reverse(n) = sum of the proper divisors of n.
%C A072234 I call these the "tcefrep numbers" ("perfect" spelled backwards). This 
               sequence lists all tcefrep numbers up to 2.28 * 10^8. Mark Ganson 
               conjectures that all tcefrep numbers are divisible by 3.
%C A072234 Jens Kruse Andersen discovered that 4158499614 is tcefrep (though this 
               may not be the next term). There are no more tcefrep numbers < 10^10.
%e A072234 The proper divisors of 498906 are 1, 2, 3, 6, 9, 18, 27, 54, 9239, 18478, 
               27717, 55434, 83151, 166302, 249453, which sum to 609894, the reverse 
               of 498906; hence 498906 is tcefrep.
%t A072234 f[n_] := FromDigits[Reverse[IntegerDigits[n]]]; Do[ If[f[n] == Apply[Plus, 
               Drop[Divisors[n], -1]], Print[n]], {n, 2, 10^9}]
%Y A072234 Cf. A069942.
%Y A072234 Sequence in context: A112642 A067503 A079288 this_sequence A115476 A116272 
               A067484
%Y A072234 Adjacent sequences: A072231 A072232 A072233 this_sequence A072235 A072236 
               A072237
%K A072234 base,more,nonn,nice
%O A072234 1,1
%A A072234 Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Jul 05 2002

Search completed in 0.001 seconds