Page 56 - Arithmetic
P. 56
Number Sequence
A number sequence is a chain of numbers following a fixed pattern. You have already learned about two number sequences – Arithmetic and Geometric Sequence.
REMEMBER:
The nth term of an A.P. is given by Tn = a + ( n – 1) d The nth term of a G.P. is given by Tn = ar( n – 1)
Special number sequences
Triangular numbers
These numbers follow the formula Tn = 𝑛3 + 𝑛
2
The series would be 1, 3, 6, 10, 15, 21,...
Square numbers
The series has all perfect squares.
Tn = n2
The series would be 1, 4, 9, 16, 25, 36, 49,....... Cube numbers
The series has all perfect cubes.
Tn = n3
The series would be 1, 8, 27, 64, 125, 216,.......
Fibonacci Numbers
The next number in a Fibonacci series is the addition of the previous two numbers. By definition, the first two numbers of the series are 0 and 1. The third number would be 1 (0+1), and the fourth number would be 2 (1+1).
The series would be
0, 1, 1, 2, 3, 5, 8, 13, 21,.....
Page 55 of 55
Arithmetic Concept
