61209

Appears in sequences

• Denominators of continued fraction convergents to sqrt(357).at n=8A041677
• Smallest positive number whose digits concatenated with all previous terms forms a perfect square.at n=3A051671
• G.f.: A(x) = Product_{n>=1} 1/(1 - A007947(n)*x^n)^(1/n), where A007947(n) is the product of the distinct prime factors of n.at n=29A094947
• Numbers n such that product of double factorials of the digits of n equals sigma(n).at n=16A158989
• 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=36A391452