2 It is g \(n\)th \(\mathrm { t } \phi ( n ) = 5 ^ { n } ( 4 n + 1 )\), ff \(\quad \mathbf { o } \quad n = , \mathbb { B } .\).
Pro tyn ath matical id tin th \(t \phi ( n )\) is \(\dot { \mathbf { d } } \dot { \mathbf { v } }\) sib eff \(\quad \mathbf { o }\) eyp itie in eg \(r n\).