OFFSET
1,1
COMMENTS
Numbers k such that k = x^4 + y^4 has a solution in positive rationals x, y.
LINKS
A. Bremner and P. Morton, A new characterization of the integer 5906, Manuscripta Math. 44 (1983) 187-229; Math. Rev. 84i:10016.
Steven R. Finch, On a generalized Fermat-Wiles equation [broken link]
Steven R. Finch, On a Generalized Fermat-Wiles Equation [From the Wayback Machine]
Eric Weisstein's World of Mathematics, Biquadratic Number
MATHEMATICA
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 *)
CROSSREFS
KEYWORD
nonn,nice,more
AUTHOR
Michel ten Voorde, Apr 04 2001
STATUS
approved