Work out hexagonal number instantly with clear inputs, formula shown and shareable results.
Hexagonal numbers are Hₙ = n(2n − 1) and count dots in nested hexagons. Every hexagonal number is also triangular, specifically H(n) = T(2n − 1).
Hexagonal number
Hₙ = n(2n − 1) = T(2n − 1)
10 × 19 = 190, which equals the 19th triangular number.
No, only those with odd index. T₄ = 10 is triangular but not hexagonal.