Finding a formula for a difficult sequence

  • Thread starter Thread starter torquerotates
  • Start date Start date
  • Tags Tags
    Formula Sequence
Click For Summary
SUMMARY

The sequence 1, 3, 6, 10 corresponds to the triangular numbers, which can be expressed with the formula a_n = ∑_{k=1}^n k = n(n + 1)/2. The differences between consecutive terms increase linearly, specifically by 1, indicating that each term is the sum of the first n natural numbers. This formula is essential for calculating the nth term of the sequence efficiently.

PREREQUISITES
  • Understanding of triangular numbers
  • Basic knowledge of summation notation
  • Familiarity with algebraic manipulation
  • Concept of sequences and series
NEXT STEPS
  • Study the derivation of the triangular number formula
  • Explore other types of number sequences, such as square and pentagonal numbers
  • Learn about mathematical induction to prove formulas for sequences
  • Investigate applications of triangular numbers in combinatorics
USEFUL FOR

Students in mathematics, educators teaching number sequences, and anyone interested in combinatorial mathematics will benefit from this discussion.

torquerotates
Messages
207
Reaction score
0

Homework Statement

I'm trying to find a formula for 1, 3, 6, 10 ... for n=2,3,4,...







The Attempt at a Solution


Well I know that the difference between each number is increasing by 1. For example, the difference between 1 and 3 is 2, between 3 and 6 is 3, between 6 and 10 is 4 and so on. But, I just don't see a formula.
 
Physics news on Phys.org
Hi! [tex]a_n = \sum_{ k = 1 }^n k = \frac{ n ( n + 1 ) }{ 2 }[/tex]
 
For some reason, I can't read that.
 

Similar threads

  • · Replies 22 ·
Replies
22
Views
2K
Replies
2
Views
5K
  • · Replies 51 ·
2
Replies
51
Views
5K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 21 ·
Replies
21
Views
3K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 2 ·
Replies
2
Views
2K