Taxicab(n) exists (Hardy and Wright, 1938)
Taxicab(5) (Wilson, 1997) 48988659276962496 =
3878733 + 36575733
= 10783933 + 36275333
= 20529233 + 34295233 =
2142433 + 33658833
= 23151833 + 33195433
Taxicab(6)?
99% probability = 24153319581254312065344
(Rathbun, 2002; Calude, Calude and Dinneen, 2003)
Are there any numbers that are a sum of two fifth powers in two ways?