오일러 프로젝트 haskell solutions
Problem 45Triangle, pentagonal, and hexagonal numbers are generated by the following formulae:Triangle Tn=n(n+1)/2 1, 3, 6, 10, 15, …Pentagonal Pn=n(3n−1)/2 1, 5, 12, 22, 35, …Hexagonal Hn=n(2n−1) 1, 6, 15, 28, 45, …It can be verified that T285 = P165 = H143 = 40755.Find the next triangle number ...