21772800

Appears in sequences

• Lah numbers: a(n) = n!*binomial(n-1,2)/6.at n=9A001754
• Largest number in n-th row of triangle of Lah numbers (A008297 and A271703).at n=10A002868
• Triangle of Lah numbers.at n=47A008297
• a(n) = n! *((-1)^n + 2*n + 3)/4.at n=10A052558
• Expansion of E.g.f. x*(1-x)/(1-x-x^3).at n=10A052605
• Expansion of e.g.f. (1+x-x^2)/((1-x)*(1-x^2)).at n=10A052689
• Euler's totient of A104350(n).at n=13A104354
• The first four terms of the sequence are doubled, then those numbers are tripled and then those numbers are quadrupled, etc.at n=38A115425
• Difference between (n!)^2 and the next smaller factorial.at n=5A121348
• Bishops on an n X n board (see Robinson paper for details).at n=20A122748
• Triangle read by rows: T(n,k) = (n + 1)*(n + k)!.at n=20A143085
• Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} for which k is the maximal number of initial even entries (0 <= k <= floor(n/2)).at n=35A152664
• Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} with maximal number of initial entries of the same parity equal to k (1 <= k <= ceiling(n/2)).at n=30A152878
• a(n) = Sum (J(p): p is a permutation of {1,2,...,n}), where J(p) is the number of j <= ceiling(n/2) such that p(j) + p(n+1-j) = n+1.at n=10A155519
• a(n) = (n+1)*(n-1)!/2.at n=8A171005
• Denominators of the swinging Bernoulli number b_n.at n=14A182918
• Triangular array read by rows: T(n,k) is the number of simple labeled graphs on n nodes with unicyclic components having exactly k nodes with degree 1; n>=3, 0<=k<=n-3.at n=35A217763
• Array of coefficients of numerator polynomials (divided by x) of the n-th approximation of the continued fraction x/(1+x/(2+x/(3+...at n=38A221913
• Number of cds-sortable permutations in S_n. That is, number of permutations for which application of some sequence of context directed swaps ("cds" operations) terminates in the identity.at n=10A249165
• Expansion of e.g.f. (1 + x)^3*log(1 + x).at n=13A274266