Question Number 77015 by aliesam last updated on 02/Jan/20
Commented by MJS last updated on 02/Jan/20
$$\mathrm{35}^{\mathrm{2}} =\mathrm{1225} \\ $$$$\mathrm{335}^{\mathrm{2}} =\mathrm{112225} \\ $$$$\mathrm{3335}^{\mathrm{2}} =\mathrm{11122225} \\ $$$$… \\ $$$$\left(\underset{{n}} {\mathrm{3}5}\right)^{\mathrm{2}} =\underset{{n}} {\mathrm{1}}\:\underset{{n}+\mathrm{1}} {\mathrm{2}}\:\mathrm{5} \\ $$$$\underset{\mathrm{1997}} {\mathrm{1}}\:\underset{\mathrm{1998}} {\mathrm{2}5}=\left(\underset{\mathrm{1997}} {\mathrm{3}5}\right)^{\mathrm{2}} \\ $$