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 A239290 #14 Oct 08 2015 07:10:45 %S A239290 4,7,8,19,55,149,497,1799,6696,26109,106953 %N A239290 Number of pairs of terms of the sequence A228126 less than 10^n. %H A239290 Giovanni Resta, <a href="http://www.numbersaplenty.com/set/eRAP/">eRAPs: the 446139 terms < 10^12</a> %H A239290 Carlos Rivera, <a href="http://www.primepuzzles.net/puzzles/puzz_719.htm">Extension to Ruth Aaron pairs</a> %Y A239290 Cf. A001414, A006145 Ruth-Aaron numbers (1): sum of prime divisors of n = sum of prime divisors of n+1, A228126 Sum of prime divisors of n (with repetition) is one less than the sum of prime divisors (with repetition) of n+1. %K A239290 nonn,hard,more %O A239290 1,1 %A A239290 _Abhiram R Devesh_, Jun 14 2014