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 A116031 #5 Mar 30 2012 17:40:36 %S A116031 4,388,403,10010,11481,12215,41242,42173,44243,223261,223487,403303, %T A116031 2302031,3288877,3490447,32605627,40077553,40162802,42311323,44044043, %U A116031 117426509,222613051,230777581,232075811,287772226,307222207,327067459 %N A116031 sigma(n)-phi(n) and sigma(n)+phi(n) are two palindromes greater than 2. %e A116031 sigma(3288877)-phi(3288877) = 44444 and %e A116031 sigma(3288877)+phi(3288877)=6577756. %Y A116031 Cf. A115897, A116030. %K A116031 nonn,base %O A116031 1,1 %A A116031 _Giovanni Resta_, Feb 13 2006 %E A116031 a(15)-a(27) from _Donovan Johnson_, Feb 05 2010