Find the sum of the series `31^3+32^3+...+50^3dot`

Find the sum of the series 3+7+14+24+37...

Find the sum of the series 3 + 7 + 13 + 21 + 31 + … to n terms . Find the sun when n=20

. Find the sum of the series 1.2+2.2^(2)+3.2^(2)+...+100.2^(100)

Find the sum of n terms of the series 1^3+3.2^2+3^3+3.4^2+5^3+3.6^2+....... when (i)n is odd (ii)n is even

Find the sum of the series : 3,-4,(16)/(3),... to 2n terms.

find the nth term and the sum of the series 2,5,12,31,86...

Find the sum of the series 1*2*3+2*3*4+3*4*5+"...." " upto n terms " .

Find the sum of the geometric series 3+6+12+...+1536 .