Question

Find the sum of the first n terms of the following
series :
${1}^{2 +} + ( {1}^{2} + {2}^{2} ) + ( {1}^{2} + {2}^{2} + {3}^{2}) + ....$
​

Answer 1

Answer:

20

Step-by-step explanation:

1^2+(1^2+2^2)+(1^2+2^2+3^2)

1+(1+4)+(1+4+9)

1+5+14

20

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