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 A008923 #8 Jul 08 2025 01:24:21 %S A008923 90239171293339457,43217672330080936976,6822171645549542113537, %T A008923 497455247066570553051152,20549128177340906621890817, %U A008923 24223393095189686902587392,549140647573975773898200592 %N A008923 Euler's family of solutions to n = x^4 + y^4 = z^4 + w^4. %D A008923 Mordell, Diophantine Equations, 1969, p. 90. %p A008923 Set x := a^7+a^5*b^2-2*a^3*b^4+3*a^2*b^5+a*b^6; y := a^6*b-3*a^5*b^2-2*a^4*b^3+a^2*b^5+b^7; z := a^7+a^5*b^2-2*a^3*b^4-3*a^2*b^5+a*b^6; w := a^6*b+3*a^5*b^2-2*a^4*b^3+a^2*b^5+b^7; then x^4+y^4=z^4+w^4. %Y A008923 Cf. A003824. %K A008923 nonn %O A008923 1,1 %A A008923 _N. J. A. Sloane_