3353011200

Appears in sequences

• Number of pairs of sequences of cardinality at least 3.at n=12A052521
• a(n) = n! *((-1)^n + 2*n + 3)/4.at n=12A052558
• E.g.f. (1-x)/(1-x-x^4).at n=12A052581
• E.g.f. (1-x^3)/(1-x^2-x^3).at n=12A052607
• Expansion of e.g.f. (1+x-x^2)/((1-x)*(1-x^2)).at n=12A052689
• a(n) = 7 * n!.at n=11A062098
• Bishops on an n X n board (see Robinson paper for details).at n=24A122748
• Triangle read by rows: T(n,k) = (n + 1)*(n + k)!.at n=27A143085
• 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=12A155519
• a(n) = (n+1)*(n-1)!/2.at n=10A171005
• 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=12A249165
• a(n) = n*(2*(n-1))! for n > 0, a(0) = 1.at n=7A327882
• Irregular triangle read by rows: T(n,k) is the number of sets of lists with distinct block sizes (as in A088311(n)) and containing exactly k lists.at n=43A351884
• Triangle read by rows: T(n, k) = (-1)^k*Product_{j=0..k-1} (j - n)*(j + n), for 0 <= k <= n.at n=34A370707