219920

Appears in sequences

• Dowling numbers: e.g.f.: exp(x + (exp(b*x) - 1)/b) with b=2.at n=8A007405
• G.f.: -x*(1-2*x+2*x^2)/(2*x^3-4*x^2+4*x-1).at n=13A078484
• Numbers m such that gcd(s1,s2) = number of the Collatz iterations of m where s1 is the sum of the odd terms and s2 the sum of the even terms in the Collatz trajectory.at n=25A281195
• Number of noncrossing partitions of an n-set up to rotation and reflection with all blocks having a prime number of elements.at n=21A303875
• Square array A(n,k), n >= 0, k >= 1, read by antidiagonals: A(n,k) = exp(-1/k) * Sum_{j>=0} (k*j + 1)^n / (k^j * j!).at n=53A334165