185794560

Appears in sequences

• Double factorial of even numbers: (2n)!! = 2^n*n!.at n=9A000165
• Sorted list of orders of Weyl groups of types A_n, B_n, D_n, E_n, F_4, G_2.at n=29A001217
• Order of orthogonal group O(n, GF(2)).at n=7A003053
• Double factorials n!!: a(n) = n*a(n-2) for n > 1, a(0) = a(1) = 1.at n=18A006882
• Denominators in the Taylor expansion exp(cosec(x)-cot(x))=1 + x/2 + x^2/8 + x^3/16 + 3*x^4/128 + 37*x^5/3840 + 59*x^6/15360 + ...at n=9A013516
• Number of solutions to non-attacking rooks problem on n X n board that are invariant under 180-degree rotation.at n=18A037223
• Number of solutions to non-attacking rooks problem on n X n board that are invariant under 180-degree rotation.at n=19A037223
• E.g.f. (1+x^2-2x^3)/(1-2x).at n=9A052576
• E.g.f. (2-2x-x^2)/((1-2x)(1-x^2)).at n=9A052647
• Expansion of e.g.f. (1 + x^3 - 2*x^4)/(1-2*x).at n=9A052694
• Denominators of series related to triangular cacti.at n=9A058928
• Denominators in the series for Bessel function J9(x).at n=0A061440
• a(n) = 2^(2n+1)*(2n+1)!.at n=4A067626
• Matrix square of unsigned Lah triangle abs(A008297(n,k)) or A105278(n,k).at n=37A079621
• a(n) = 2^(n^2 + 2n + 1)*Product_{j=1..n} (4^j - 1).at n=3A090770
• Startorial numbers: product of initial digits of integers 1 through n.at n=27A109834
• 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=17A110144
• Number of permutations on 1..n where gcd(s_i,n) = gcd(i,n). Also Product_{d divides n} phi(d)!.at n=23A120065
• Triangle of coefficients p(k, x), where p(k, x) = 2*(k-1)*p(k-1, x) -x*p(k-2, x), read by rows.at n=35A123235
• Triangle: No(x, n) = (2*n/x)*No(x, n - 1) + (-n/(n - 2))*No( x, n - 2) + Ceiling[(2*(n - 1)/((n - 2)))*Sin[(n - 1)*Pi/2]]/x; weighted by 2*x^(n + 1).at n=41A137384