257724

Appears in sequences

• Numbers n such that n and n+1 both have 18 divisors.at n=26A274360
• a(n) is the number of 5 element sets of distinct integer-sided trapezoids whose base angles are 60 degrees that fill an equilateral triangular grid of side n units without partitioning a triangle into 3 element sets of trapezoids.at n=51A391452