55800

Appears in sequences

• Number of sublattices of index n in generic 4-dimensional lattice.at n=23A038991
• Numbers m such that sigma(m)/m is equal to sigma(k)/k for some k being superabundant (A004394).at n=38A073349
• Fifth column of the (1,4)-Pascal triangle A095666.at n=29A095667
• Table (read by rows) giving the coefficients of sum formulas of n-th Factorials (A000142). The k-th row (k>=1, n>=2) contains T(i,k) for i=1 to k+1, where k=[2*n+1+(-1)^(n-1)]/4 and T(i,k) satisfies Fact(n) = Sum_{i=1..k+1} T(i,k) * (n-1)^(k-i+1) / (2*k-2)!.at n=10A101751
• Odd triangle n!. This table read by rows gives the coefficients of sum formulas of n-th Factorials (A000142). The k-th row (6>=k>=1) contains T(i,k) for i=1 to k+2, where k=[2*n+3+(-1)^n]/4 and T(i,k) satisfies n! = Sum_{i=1..k+2} T(i,k) * n^(i-1) / (2*k-2)!.at n=15A102410
• Triangle read by rows: T(n,k) is the number of partitions of the set {1,2,...,n} having exactly k blocks that contain both odd and even entries (0<=k<=floor(n/2)).at n=40A124418
• Triangle read by rows: T(n,k) = number of simple graphs on n labeled nodes with k edges that are node-disjoint unions of undirected cycle subgraphs.at n=62A144161
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 0, 1), (0, 0, -1), (1, 1, 1)}.at n=10A149237
• Corresponding values of arithmetic means of divisors of numbers from A007340.at n=33A157848
• Numbers m such that m = s|t = phi(s)*sigma(t) for some numbers s and t, where "|" denotes concatenation.at n=3A159000
• Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having exactly k odd fixed points (0 <= k <= ceiling(n/2)).at n=45A161133
• Molecular topological indices of the complete graph K_n.at n=30A181617
• Numbers with prime factorization p*q^2*r^2*s^3 (where p, q, r, s are distinct primes).at n=20A190109
• Irregular triangular array read by rows: T(n,k) is the number of inequivalent n X n {0,1} matrices modulo permutation of the rows, containing exactly k 1's; n>=0, 0<=k<=n^2.at n=47A220886
• Irregular triangular array read by rows: T(n,k) is the number of inequivalent n X n {0,1} matrices modulo permutation of the rows, containing exactly k 1's; n>=0, 0<=k<=n^2.at n=48A220886
• Number of n X 2 0..n+2-2 arrays with upper left zero and lower right n+2-2 and each element differing from its diagonal and antidiagonal neighbors by one or two.at n=5A265474
• Number of nX6 0..n+6-2 arrays with upper left zero and lower right n+6-2 and each element differing from its diagonal and antidiagonal neighbors by one or two.at n=1A265478
• T(n,k)=Number of nXk 0..n+k-2 arrays with upper left zero and lower right n+k-2 and each element differing from its diagonal and antidiagonal neighbors by one or two.at n=22A265480
• T(n,k)=Number of nXk 0..n+k-2 arrays with upper left zero and lower right n+k-2 and each element differing from its diagonal and antidiagonal neighbors by one or two.at n=26A265480
• Numbers m that can be written as x*y with phi(x)*sigma(y) = 2*x*y, where x and y are positive integers, phi(.) is Euler's totient function and sigma(y) is the sum of all positive divisors of y.at n=39A279915