18021
domain: N
Appears in sequences
- Number of factorization patterns of polynomials of degree n over F_4.at n=21A006169
- a(n) = floor(C(4n,2n)/C(4n,n)).at n=19A024501
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 68 ones.at n=31A031836
- Positions of zeros in A165597.at n=32A165598
- Number of ordered triples (w,x,y) with all terms in {1,...,n} and 2w^2>x^2+y^2.at n=33A211810
- Number of (w,x,y,z) with all terms in {1,...,n} and 3w=x+y+z+n.at n=35A212247
- Number of minimal edge covers in the n-double cone graph.at n=8A379182