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 A122540 #1 Sep 29 2006 03:00:00 %S A122540 2,137633,409698593 %N A122540 Primes that can be written in n ways as the sum of three fourth powers. %C A122540 If you replace 'prime' with 'odd number', the sequence is 17, 2673, 16196193, 155129315313, ... Next term is at least 3000^4. %C A122540 The restriction to primes is quite severe and to odd numbers reasonably so; otherwise x^4+y^4+(x+y)^4=2(x^2+xy+y^2)^2 gives very many examples of the form 2k^2. %e A122540 a(2)=137633; 8^4+13^4+18^4 = 9^4+16^4+16^4 and this is the smallest prime N for which this holds %e A122540 a(3)=409698593; 128^4+109^4+18^4 = 129^4+94^4+86^4 = 142^4+42^4+1 %Y A122540 Obvious variant on A085559. %K A122540 hard,more,nonn,bref %O A122540 1,1 %A A122540 Thomas Womack (tom(AT)womack.net), Sep 19 2006