cabtaxi number

A cabtaxi numberMathworldPlanetmath for a given n is the smallest positive number which can be written as a3+b3 in n different ways, with either a or b allowed to be negative integers. For example, 91 is the 2nd cabtaxi number since it can be expressed (-5)3+63=33+43=91. The known cabtaxi numbers are 1, 91, 728, 2741256, 6017193, 1412774811, 11302198488, 137513849003496, 424910390480793000, listed in A047696 of Sloane’s OEIS. Adding the restrictionPlanetmathPlanetmath ab>0 gives the definition for the taxicab numbersMathworldPlanetmath.

Title cabtaxi number
Canonical name CabtaxiNumber
Date of creation 2013-03-22 17:56:08
Last modified on 2013-03-22 17:56:08
Owner PrimeFan (13766)
Last modified by PrimeFan (13766)
Numerical id 4
Author PrimeFan (13766)
Entry type Definition
Classification msc 00A08