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 A071525 #15 Dec 15 2017 17:35:55 %S A071525 1,3,304,918,23922,2388063,88423222968,655516144546 %N A071525 Numbers n such that sigma(phi(n)) = reversal(n). %C A071525 There are no other terms up to 10^7. - _Jason Earls_, Jun 04 2002 %C A071525 There are no other terms up to 45*10^7. - _Farideh Firoozbakht_, Dec 26 2007 %C A071525 There are no other terms up to 10^10. - _Donovan Johnson_, Oct 24 2013 %C A071525 a(9) > 10^12. - _Giovanni Resta_, Nov 10 2017 %e A071525 sigma(phi(304)) = 403 = reverse(304). %t A071525 Select[Range[10^5], DivisorSigma[1, EulerPhi[ # ]] == FromDigits[Reverse[IntegerDigits[ # ]]] &] %Y A071525 Cf. A000010, A000203, A135238. %K A071525 base,nonn %O A071525 1,2 %A A071525 _Joseph L. Pe_, Jun 02 2002 %E A071525 More terms from _Jason Earls_, Jun 04 2002 %E A071525 Definition restored by _Farideh Firoozbakht_, Dec 26 2007 %E A071525 a(7)-a(8) from _Giovanni Resta_, Nov 10 2017