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 A230562 #22 Mar 14 2015 10:10:50 %S A230562 0,2,635318657 %N A230562 Smallest number that is the sum of 2 positive 4th powers in >= n ways. %C A230562 Hardy and Wright say that a(3) is unknown. %C A230562 Guy, 2004: "Euler knew that 635318657 = 133^4 + 134^4 = 59^4 + 158^4, and Leech showed this to be the smallest example. No one knows of three such equal sums." %D A230562 R. K. Guy, Unsolved Problems in Number Theory, 3rd edition, Springer, 2004, D1 %D A230562 G. H. Hardy and E. M. Wright, An Introduction to the Theory of Numbers, 6th edition, 2008; section 21.11. %H A230562 Carlos Rivera, <a href="http://www.primepuzzles.net/puzzles/puzz_103.htm">Puzzle 103: N = a^4 + b^4 = c^4 + d^4</a> %e A230562 0 = (empty sum). %e A230562 2 = 1^4 + 1^4. %e A230562 635318657 = 59^4 + 158^4 = 133^4 + 134^4. %Y A230562 Cf. A003824, A016078, A018786, A046881, A088687, A088848, A088849, A088867, A230561. %K A230562 hard,more,nonn %O A230562 0,2 %A A230562 _Jonathan Sondow_, Oct 25 2013