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 A072234 #29 Dec 30 2024 19:22:29
%S A072234 6,498906,20671542,41673714,73687923,4158499614,922964834547
%N A072234 Numbers k such that reverse(k) = sum of the proper divisors of k.
%C A072234 Mark Ganson conjectures that all terms are divisible by 3.
%C A072234 Jens Kruse Andersen discovered that 4158499614 is in the sequence (although he did not rule out the possibility that there were missing terms below this - that was established by _Giovanni Resta_).
%C A072234 a(8) > 10^13. - _Giovanni Resta_, Dec 12 2013
%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 a term of the sequence.
%t A072234 f = IntegerReverse; Do[ If[f[n] == Apply[Plus, Drop[Divisors[n], -1]], Print[n]], {n, 2, 10^9}]
%t A072234 Select[Range[500000],IntegerReverse[#]==Total[Most[Divisors[#]]]&] (* The program generates the first 2 terms of the sequence. To generate more, increase the Range constant but the program may take a long time to run. *) (* _Harvey P. Dale_, Dec 30 2024 *)
%o A072234 (PARI) for(n=1,10^9,if(sigma(n)-n==eval(concat(Vecrev(Str(n)))),print1(n,","))) \\ _Edward Jiang_, Sep 10 2014
%Y A072234 Cf. A001065, A004086, A069942.
%K A072234 base,more,nonn,nice
%O A072234 1,1
%A A072234 _Joseph L. Pe_, Jul 05 2002
%E A072234 a(6) confirmed and a(7) discovered by _Giovanni Resta_, Dec 12 2013