18857
domain: N
Appears in sequences
- a(n) = Sum_{y=1..n} Sum_{x=1..n} floor((x^k + y^k)^(1/k)) with k = 2.at n=28A211791
- O.g.f.: Sum_{n>=0} 1/(1-n^2*x)^n * x^n/n! * exp(-x/(1-n^2*x)).at n=7A218668
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 123", based on the 5-celled von Neumann neighborhood.at n=29A270212
- Index of the smaller Ulam number of record gaps (A080287).at n=20A274522
- a(n) = a(n-1) + 3*a(n-2) -2*a(n-3) - 2*a(n-4), where a(0) = 1, a(1) = -2, a(2) = 2, a(3) = 1.at n=18A295855
- Expansion of (1/x) * Series_Reversion( x*(1-x)^3/(1-x-x^2) ).at n=8A366082
- Odd semiprimes p*q, such that Stern polynomial B(p*q,x) is a product of B(p,x) and B(q,x).at n=44A391256