18570

Appears in sequences

• Number of polyhexes with n hexagons, having reflectional symmetry (see Harary and Read for precise definition).at n=16A002215
• Catafusenes (see reference for precise definition).at n=16A044044
• Numbers whose base-4 representation contains exactly three 0's and four 2's.at n=26A045056
• a(n) = a(1) + a(2) + ... + a(n-1) - a(m) for n >= 4, where m = n - 1 - 2^p and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1, a(2) = 2, and a(3) = 3.at n=15A049910
• a(n) is the minimal area of a convex lattice polygon with 2n sides.at n=49A089187
• Expansion of 1 - 3*x - sqrt(1 - 6*x + 5*x^2).at n=8A122737
• Triangle read by rows: T(n,k) is the number of skew Dyck paths of semilength n and having k returns to the x-axis (1 <= k <= n).at n=36A128741
• 4^n + 3^n - 1.at n=7A155602
• Number of (n+1) X 3 0..1 arrays with column and row pair sums b(i,j)=a(i,j)+a(i,j-1) and c(i,j)=a(i,j)+a(i-1,j) nondecreasing in column and row directions, respectively.at n=27A204645
• Numbers k such that Bernoulli number B_{k} has denominator 14322.at n=25A295588
• G.f. satisfies: A(x) = Sum_{n>=0} binomial(n*(n+1),n)/(n+1) * x^n/A(x)^n.at n=5A295763
• a(n) is the smallest number that can be partitioned into n ways as the sum of two Moran numbers.at n=37A337862
• Number of ways to write n as an ordered sum of 10 squares of positive integers.at n=44A340947