Triangle, 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 that is also pentagonal and hexagonal.