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 A366703 #12 Oct 18 2023 10:04:24
%S A366703 7,239,157,227,40351,62047,46747,59693
%N A366703 List of quadruples (a,b,c,d) with a^4 + b^4 = c^4 + d^4, a < c < d < b, a,b,c,d prime, listed in order of the largest term b.
%C A366703 See A255352 for quadruples which do not necessarily consist of prime numbers. There are infinitely many such quadruples, because if (a, b, c, d) is in the sequence, so is (m*a, m*b, m*c, m*d). It is unknown whether there are infinitely many quadruples which consist only of prime numbers. The two given quadruples are the only ones with a^4 + b^4 = c^4 + d^4 <= 10^24.
%H A366703 Mia Müßig, <a href="https://github.com/PhoenixSmaug/taxicab-numbers">Julia code for finding general taxicab numbers</a>.
%e A366703 The quadruples (a,b,c,d), listed in order of increasing b = max{a,b,c,d}, are
%e A366703 (7, 239, 157, 227),
%e A366703 (40351, 62047, 46747, 59693), ...
%Y A366703 Cf. A018786, A255351, A255352.
%K A366703 nonn,hard,more
%O A366703 1,1
%A A366703 _Mia Muessig_, Oct 17 2023