Find the next three terms of the sequences.
 \(\frac { 1 }{ 2 } ,\frac { 1 }{ 6 } ,\frac { 1 }{ 10 },\frac { 1 }{ 14 } \), ..... ,

The general term of a sequence is defined as 
a_n = \(\begin{cases} n\left( n+3 \right) ;n\in N\quad is\quad odd \\ { n }^{ 2 }+1;n\in N\quad is\quad even \end{cases}\)
Find the eleventh and eighteenth terms.

Find a₈ and a₁₅ whose n^th term is
a_n = \(\begin{cases} \frac { { n }^{ 2 }-1 }{ n+3 } ;n\quad is\quad even,\quad n\epsilon N \\ \begin{matrix} \\ \frac { { n }^{ 2 } }{ 2n+1 } ,n\quad is\quad odd,\quad n\epsilon N \end{matrix} \end{cases}\)

First term a and common difference d are given below. Find the corresponding A.P
a = 5, d = 6

How many consecutive odd integers beginning with 5 will sum to 480?

Find the 8^th term of the G.P 9,3,1,....

Find the sum of
1³ + 2³ + 3³ +..+ 16³

Find the least positive value of x such that
98 \(\equiv \)  (x + 4) (mod 5)

Check whether the following sequences are in A.P.
 9, 13, 17, 21, 25,... ,

Find the sum of the following series
1 + 4 + 9 + 16 +..+ 225