18500

Appears in sequences

• Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 68.at n=3A031746
• Number of solutions to n^2 < x^2 + y^2 + z^2 < (n+1)^2; number of lattice points between spheres of radii n and n+1.at n=38A078184
• Even numbers n such that 37^2 (the square of the first irregular prime) divides the numerator of Bernoulli(n).at n=33A090789
• a(n) = 16*n^2 + 4.at n=33A158444
• a(n)=a(n-2)+64*a(n-3) with a(0)=1, a(1)=4, a(3)=16.at n=7A158761
• Positions where A163890 obtains distinct new values.at n=22A163891
• Triangle by rows T(n,k), showing the number of meanders with length (n+1)*3 and containing (k+1)*3 L's and (n-k)*3 R's, where L's and R's denote arcs of equal length and a central angle of 120 degrees which are positively or negatively oriented.at n=24A194595
• Number of 0..4 arrays x(0..n-1) of n elements with nondecreasing average value and 0..4 occur with instance counts within one of each other.at n=13A200940
• Square array A(n,k), n>=1, k>=1, read by antidiagonals: A(n,k) is the number of n-colorings of the complete bipartite graph K_(k,k).at n=32A212085
• a(n) = (A278399(n)^2 + A278400(n)^2)/2.at n=36A278420
• a(n) = sigma_2(3*n).at n=42A283237
• Practical numbers z such that z^2 = x^2 + y^2 for some practical numbers x and y with gcd(x,y,z) = 4.at n=30A294112
• Number of nX3 0..1 arrays with every element equal to 1, 2, 3, 4 or 7 king-move adjacent elements, with upper left element zero.at n=5A298542
• Number of nX6 0..1 arrays with every element equal to 1, 2, 3, 4 or 7 king-move adjacent elements, with upper left element zero.at n=2A298545
• T(n,k)=Number of nXk 0..1 arrays with every element equal to 1, 2, 3, 4 or 7 king-move adjacent elements, with upper left element zero.at n=30A298547
• T(n,k)=Number of nXk 0..1 arrays with every element equal to 1, 2, 3, 4 or 7 king-move adjacent elements, with upper left element zero.at n=33A298547
• Number of nX3 0..1 arrays with every element unequal to 0, 1, 2, 4, 6 or 8 king-move adjacent elements, with upper left element zero.at n=10A316299
• Number of integer partitions of n whose run-lengths are either weakly increasing or weakly decreasing.at n=41A332745
• Number of odd digits necessary to write all nonnegative n-digit integers.at n=3A359271
• 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 with a trapezoid filled by 3 trapezoids.at n=26A391204