18144000

Appears in sequences

• Number of pairs of sequences of cardinality at least 3.at n=10A052521
• Expansion of e.g.f. x/((1-x)(1-x^2)).at n=10A052591
• Expansion of e.g.f. 5*x/(1-x).at n=10A052648
• Expansion of e.g.f. x^2/((1-x)^2*(1+x)).at n=10A052657
• a(1) = 1; a(n) = n * Sum_{k=1..n-1} a(k).at n=9A074143
• a(n) = n! / A003040(n).at n=15A082914
• Duplicate of A082914.at n=15A092031
• Unsigned member s=2 of a family of generalizations of the (signed) Lah triangle A008297. All numbers divided by 2.at n=37A136657
• Elements n of A141586 with property that A100762(n) = n.at n=36A141758
• Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k adjacent pairs of the form (even,even) (0<=k<=floor(n/2)-1).at n=29A145892
• Number of permutations of [n] for which the first two entries have the same parity (n>=2).at n=9A152661
• 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 odd entries (0 <= k <= ceiling(n/2)).at n=41A152662
• Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k runs of even entries (n >= 2, 1 <= k <= floor(n/2)). For example, the permutation 321756498 has 3 runs of even entries: 2, 64 and 8.at n=27A152667
• Number of endofunctions on [n] where the smallest cycle length equals 8.at n=2A246195
• Number of endofunctions on [n] whose cycle lengths are multiples of 8.at n=10A246615
• Number of primitive (=aperiodic) n-bead necklaces with colored beads of exactly 10 different colors.at n=1A254082
• G.f.: C(x,y)^2 - S(x,y)^2 = Sum_{n>=0} x^(2*n)*y/[Sum_{k=0..2*n+1} T(n,k)*y^k], where C(x,y) = Sum_{n>=0} x^(2*n) / Product_{k=1..2*n} (k + y) and S(x,y) = Sum_{n>=0} x^(2*n+1) / Product_{k=1..2*n+1} (k + y).at n=30A268647
• Number of endofunctions on [n] such that the LCM of their cycle lengths equals five.at n=9A291111
• Triangle read by rows: denominators of c_{n,k}, n >= 0, k = 0..n, used in the proof that Zeta(3) is irrational.at n=25A303989
• GCD of consecutive terms of the factorial times the alternating harmonic series.at n=14A334958