Class 11MathematicsSequences and Seriesnth term of special series, Sum to n terms and Infinite number of terms
EasyWhat is the $20^{\text{th}}$ term of the sequence defined by $a_{n} = (n-1)(2-n)(3+n)$?
- A$-7866$
- B$-7860$
- C$-7872$
- D$-7854$
Explore More
Similar Questions
The sum of the first $20$ terms of the sequence $0.7, 0.77, 0.777, \dots$ is
$\sum_{k=1}^{\infty} \sum_{r=0}^k \frac{1}{3^k} \binom{k}{r}$ is equal to
DifficultAP EAMCET 2012
View Solution$11^2 + 12^2 + 13^2 + \dots + 20^2 = ?$
Medium
View SolutionLet $n$ be the smallest positive integer such that $1+\frac{1}{2}+\frac{1}{3}+\ldots+\frac{1}{n} \geq 4$. Which one of the following statements is true?
Let $f(n) = \left[ \frac{1}{3} + \frac{3n}{100} \right]n$,where $[x]$ denotes the greatest integer less than or equal to $x$. Then $\sum_{n=1}^{56} f(n)$ is equal to
DifficultJEE MAIN 2014
View SolutionVedclass Products
For Students
Vedclass Test Series
Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.
Start Free TrialFor Teachers
Exam Paper Generator
Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.
Try FreeFor Institutes
Online Exam Module
Live online exams with unlimited students, 360° analytics & white-label branding.
See Demo