91 = 12 + 22 + 32 + 42 + 52 + 62
91 = 1 + 2 + 3 + ... + 12 + 13
{\displaystyle {\begin{matrix}\mathrm {Cabtaxi} (2)&=&91&=&3^{3}+4^{3}\\&&&=&6^{3}-5^{3}\end{matrix}}}
Undergraduate Texts in Mathematics
Graduate Studies in Mathematics
91
91 = 12 + 22 + 32 + 42 + 52 + 62
91 = 1 + 2 + 3 + ... + 12 + 13
{\displaystyle {\begin{matrix}\mathrm {Cabtaxi} (2)&=&91&=&3^{3}+4^{3}\\&&&=&6^{3}-5^{3}\end{matrix}}}
Undergraduate Texts in Mathematics
Graduate Studies in Mathematics