[seqfan] Re: n = 562576374032409

[Giovanni Resta]

On 05/26/2016 07:13 PM, Zak Seidov via SeqFan wrote:
>   Integer n = 562576374032409 is unique in the sense that
> n and n+1 are sums of two cubes and also n is the taxi-cab number

> Is n the least such number?

There are 5 smaller such numbers:

18426689288 = 2514^3 + 1364^3 = 2498^3 + 1416^3,
18426689289 = 2641^3 + 182^3,

20689194392 = 2492^3 + 1734^3 = 2726^3 + 756^3,
20689194393 = 2282^3 + 2065^3,

166940780112 = 4683^3 + 4005^3 = 5034^3 + 3402^3,
166940780113 = 4764^3 + 3889^3,

3956149616328 = 14562^3 + 9540^3 = 14756^3 + 9058^3,
3956149616329 = 15796^3 + 2457^3,

53611112714103 = 31023^3 + 28746^3 = 35262^3 + 21375^3,
53611112714104 = 37009^3 + 14295^3.

And no other such numbers below 1.7*10^15.

Giovanni Resta