73722

Appears in sequences

• Start with a single triangle; at n-th generation add a triangle at each vertex, allowing triangles to overlap; sequence gives number of triangles in n-th generation.at n=27A061776
• a(n) = 9*2^n - 6.at n=13A089143
• Number of maximal subsets of {1..n} such that every ordered pair of distinct elements has a different difference.at n=34A325879