The Second decagonal numbers series can be represented as
7, 22, 45, 76, 115, 162, 217, 280,,…..
Given an integer N. The task is to find the N-th term of the given series.
Input: N = 1
Input: N = 4
Approach: The idea is to find the general term for the Second decagonal numbers. Below is the computation of the general term for second decagonal numbers:
1st Term = 1 * (4*1 + 3) = 7
2nd term = 2 * (4*2 + 3) = 22
3rd term = 3 * (4*3 + 3) = 45
4th term = 4 * (4*4 + 3) = 76
Nth term = n * (4 * n + 3)
Therefore, the Nth term of the series is given as
Below is the implementation of above approach:
Time Complexity: O(1)
Auxiliary Space: O(1)
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