10321920

Appears in sequences

• Double factorial of even numbers: (2n)!! = 2^n*n!.at n=8A000165
• Sorted list of orders of Weyl groups of types A_n, B_n, D_n, E_n, F_4, G_2.at n=26A001217
• Denominators of coefficients of log(1+x)/sqrt(1+x).at n=9A002550
• Double factorials n!!: a(n) = n*a(n-2) for n > 1, a(0) = a(1) = 1.at n=16A006882
• Number of subgroups L of Z^n with the property that for every a in Z^n there exists precisely one b in L with d(a,b) <= 1. Here d denotes Euclidean distance.at n=9A026739
• a(n) = (Product_{j=1..n-1} (2^j-1)) * 2^binomial(n+1,2).at n=5A028368
• Number of solutions to non-attacking rooks problem on n X n board that are invariant under 180-degree rotation.at n=16A037223
• Number of solutions to non-attacking rooks problem on n X n board that are invariant under 180-degree rotation.at n=17A037223
• Signed double Pochhammer triangle: expansion of x(x-2)(x-4)..(x-2n+2).at n=36A039683
• E.g.f. (1+x^2-2x^3)/(1-2x).at n=8A052576
• Expansion of e.g.f. (1 + x^3 - 2*x^4)/(1-2*x).at n=8A052694
• Denominators of series related to triangular cacti.at n=8A058928
• Denominators in the series for Bessel function J8(x).at n=0A061407
• Product of numbers <= n that have a prime factor in common with n.at n=15A066570
• Product of nonzero digits of A066547(n).at n=22A066581
• a(n) = 2^(2*n)*(2*n)!.at n=4A067624
• a(n) is the denominator of the polynomial in e^2 giving the (2n)th du Bois Reymond constant.at n=7A085466
• Triangle of certain double factorials.at n=44A092081
• Number of regular (4n+3)-dimensional simplices that can be inscribed on the vertices of a (4n+3)-dimensional hypercube.at n=2A108973
• Terms of A110142 at positions p(n)+1, where p(n) = A000041(n) is the number of partitions of n; a(n) = A110142(p(n)+1) for n>=1, with a(0) = 1.at n=15A110144