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 A060387 #31 Aug 11 2025 08:47:22
%S A060387 2,17,32,82,97,162,257,272,337,512,626,641,706,881,1250,1297,1312,
%T A060387 1377,1552,1921,2402,2417,2482,2592,2657,3026,3697,4097,4112,4177,
%U A060387 4352,4721,4802,5392,5906
%N A060387 Numbers k such that x^4 + y^4 = k * z^4 is solvable in nonzero integers x,y,z.
%C A060387 Numbers k such that k = x^4 + y^4 has a solution in positive rationals x, y.
%H A060387 A. Bremner and P. Morton, <a href="https://gdz.sub.uni-goettingen.de/id/PPN365956996_0044">A new characterization of the integer 5906</a>, Manuscripta Math. 44 (1983) 187-229; Math. Rev. 84i:10016.
%H A060387 Steven R. Finch, <a href="http://www.people.fas.harvard.edu/~sfinch/csolve/fermat.pdf">On a generalized Fermat-Wiles equation</a> [broken link]
%H A060387 Steven R. Finch, <a href="http://web.archive.org/web/20010602030546/http://www.mathsoft.com/asolve/fermat/fermat.html">On a Generalized Fermat-Wiles Equation</a> [From the Wayback Machine]
%H A060387 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/BiquadraticNumber.html">Biquadratic Number</a>
%t A060387 r[n_, z_] := Reduce[0 < x <= y && x^4 + y^4 == n*z^4, {x, y}, Integers]; zm[_] = 1; zm[5906] = 17; ok[n_] := (tf = False; Do[ If[ r[n, z] =!= False, tf = True; Break[]], {z, 1, zm[n]}]; tf); A060387 = Reap[ Do[ If[ ok[n], Print[n]; Sow[n]], {n, 1, 5906}]][[2, 1]](* _Jean-François Alcover_, Mar 09 2012 *)
%Y A060387 5906 is the first term not in A003336. Cf. A020897.
%Y A060387 Cf. A111152, A209431.
%K A060387 nonn,nice,more
%O A060387 1,1
%A A060387 _Michel ten Voorde_, Apr 04 2001