Find the nth term and sum to n tems of the following series: 2+6+12+20+…

Find the nth term and sum to n tems of the following series: 1+5+12+22+…………..

Find the nth term and sum to n tems of the following series: 3+6+11+18+…

Find the nth term and sum to n tems of the following series: 3+15+35+63+……..

Find the sum of n terms and sum to infinity of the following series : (1)/(2cdot4)+(1)/(4cdot6)+(1)/(6cdot8)+…

Find the nth term and the sum of n term of the series 2, 12, 36, 80, 150, 252

Find the nth term and sum to n terms of the series 12+40+90+168+280+432+"...." .

41: Find the nth term and the sum of n term of the series 2+12+36+80+150+252+.........

Find the nth term and the sum of n term of the series 6+9+21+69+261+ ………………...