The sum of the series `1.2 + 2.3+ 3.4+……..` up to 20 tems is

The sum of the series 1^2+3^2+5^2+ ........ n

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

Sum of series 1 + 2x + 7x^2 + 20x^3 + ....... up to n terms when x = - 1 is

The sum to 100 terms of the series 1.2.3. + 2.3.4. + 3.4.5. + …+ n(n + 1) (n+2) + …. is integral multiple of

Find the sum to n terms of the series (1.2.3) + (2.3.4) + (3.4.5) ...

The sum of the series 5/(1. 2.3)+7/(3. 4.5)+9/(5. 6.7)+ ....is equal to

The sum of the series 1/2x^2+2/3x^3+3/4x^4+4/5x^5+ ... is :

The sum of the series : 1 + (1)/(1 + 2) + (1)/(1 + 2 + 3)+ .... up to 10 terms, is

Find the nth term and the sum to n terms of the series 1.2+ 2.3 +3.4 + ...

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 :