A sequence is defined as following.`( n(n+2)`, if `n` is an even natural number. `(4n)/(n^2+1)`, if `n` is an odd natural number. Find the value of `18^(th)` and `25^(th)` term

If the sum of first n odd natural number is 1225, find the value of n.

Find the 18th and 25th terms of the sequence defined by : t_n= {(n(n+2),if n is even natural number),((4n)/(n^2+1), if n is odd natural number):} .

a. Find the 21 st and 42 nd terms of the sequence defined by: t_(n)={(0,"if n is odd"),(1,"if n is even"):} (b) Find the 18 th and 25 th terms of the sequence defined by t_(n)={(n(n+2),"if n is even natural number"),((4n)/(n^(2)+1),"ifn is odd natural number"):} (c) Find the 440th and 441st terms of the sequance given by: t_(n)={(n/(n/44-1),"If n is not the square ofa natural nunber"),(2.7,"if n is the square of a natural number"):}

If the sum of first n even natural number is 240. find the value of n.

If the sum of first n even natural number is 240. find the value of n.

If the sum of first n even natural numbers is 420, find the value of n.

If the sum of first "n" even natural numbers is 420, find the value of n.

If the variance of lst.n even natural numbers is 65, find the value of n

The sum of n natural numbers is 5n^2+4n . Find the 8th term.