How to find the 4th special number among pentagonal and triangular numbers
1 view (last 30 days)
Show older comments
A pentagonal number is defined by p(n) = (3n^2 – n)/2, where n is an integer starting from 1. Therefore, the first 12 pentagonal numbers are 1, 5, 12, 22, 35, 51, 70, 92, 117, 145, 176 and 210.
A triangular number is defined by t(n) = (n^2 + n)/2, where n is an integer starting from 1. Therefore, the first 12 triangular numbers are 1, 3, 6, 10, 15, 21, 28, 36, 45, 55, 66 and 78.
From the above example, the number 1 is considered 'special' because it is both a pentagonal (p=1) and a triangular number (t=1). Determine the 4th 'special' number (i.e. where p=t) that exists assuming the number 1 to the be first 'special' number.
0 Comments
Accepted Answer
More Answers (0)
See Also
Categories
Find more on Data Type Conversion in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!