25401600

Appears in sequences

• a(n) = (2*n)!*(2*n+1)! / n!^2.at n=4A000909
• a(n) = (n!)^2.at n=7A001044
• Denominator of constant term in polynomial arising from numerical integration formula.at n=8A002670
• a(n) = binomial(n,floor(n/2))*(n+1)!.at n=8A002867
• Triangle of central factorial numbers |t(2n,2n-2k)| read by rows.at n=35A008955
• Multiply successively by 1,1,2,2,3,3,4,4,..., n >= 1, a(0) = 1.at n=14A010551
• Unary-binary rooted trees with n nodes.at n=10A029766
• Sets record for f(n) = |{(a,b):a*b=n and a|b}|. Also squares of highly composite numbers A002182.at n=18A046952
• Number of pairs of sequences of cardinality at least 2.at n=10A052520
• E.g.f. 1/(1-x^2-x^3).at n=10A052597
• Expansion of e.g.f. (1+x-x^3)/((1-x)*(1-x^2)).at n=10A052687
• a(n) = (prime(n)!)^2.at n=3A061024
• Triangle of generalized Stirling numbers.at n=27A061692
• a(n) = 7 * n!.at n=9A062098
• Number of permutations of degree n with greatest sum of distances.at n=14A062870
• Triangle T(n,k) (1 <= k <= n) where the first column (T(n,1)) is the sequence of secant numbers A000364.at n=27A064670
• Smallest square divisible by n!.at n=9A065886
• Smallest square divisible by n!.at n=10A065886
• Order of the subgroup of the symmetric group S_(2n) generated by the 2 cycles: (1,2,...n,2n,2n-1,...,n+1) and (1,2,...,2n).at n=5A070740
• Triangle of coefficients of Bateman polynomial n!Z_n(-x).at n=38A073768