91800

Appears in sequences

• Values of Newton-Gregory forward interpolating polynomial (1/3)*(n-1)*(2*n+3)*(2*n-1).at n=41A030440
• Triangle of coefficients of certain Sheffer-polynomials.at n=24A048870
• Numbers n such that n | (sigma_5(n) - phi(n)^5).at n=27A055699
• Number of nonisomorphic unrooted unicursal planar maps with n edges and two vertices of valency 1 (unicursal means that exactly two vertices are of odd valency; there is an Eulerian path).at n=8A069725
• Consider the base-7 Kaprekar map n->K(n) defined in A165071. Sequence gives numbers belonging to cycles, including fixed points.at n=16A165076
• Consider the base-7 Kaprekar map n->K(n) defined in A165071. Sequence gives numbers belonging to cycles of length greater than 1.at n=15A165078
• Numbers with prime factorization pq^2r^3s^3.at n=5A190320
• Number of (w,x,y,z) with all terms in {1,...,n} and w+x<=2y+2z.at n=18A212563
• Coreful 3-abundant numbers: numbers k such that csigma(k) > 3*k, where csigma(k) is the sum of the coreful divisors of k (A057723).at n=32A340109
• Let d(1)<d(2)<...<d(q) denote the divisors of an integer k. a(n) = k is the smallest k such that the sum of its first n divisors, s = d(1) + ... + d(n), is also a divisor of k.at n=41A375574