Sum of the series S = `1 + (1)/(2)(1 + 2) + (1)/(3) ( 1 + 2 + 3 ) + (1)/(4) ( 1 + 2 + 3 + 4 ) + ……` upto 20 terms is

Sum to n terms the series 1 + (1+ 2) + (1 + 2 + 3) + (1 + 2 + 3 + 4).......

Find sum of the series upto n terms 1+(1+2)/(2)+(1+2+3)/(3)+(1+2+3+4)/(4)+

The sum of the series (1)/(1.2)-(1)/(2.3)+(1)/(3.4)-(1)/(4.5)+... is

find the sum of the series upto n terms 1+(1+2)/(2)+(1+2+3)/(3)+(1+2+3+4)/(4)+

The sum of the series 1+ 2/3+ (1)/(3 ^(2)) + (2 )/(3 ^(3)) + (1)/(3 ^(4)) + (2)/(3 ^(5)) + (1)/(3 ^(6))+ (2)/(3 ^(7))+ …… upto infinite terms is equal to :

The sum of the series 1+ 2/3+ (1)/(3 ^(2)) + (2 )/(3 ^(3)) + (1)/(3 ^(4)) + (2)/(3 ^(5)) + (1)/(3 ^(6))+ (2)/(3 ^(7))+ …… upto infinite terms is equal to :

Find the sum of the series 1+ (1+2) + (1+2+3) + (1+2 + 3 +4)+ … + (1+2+3+… + 20) .