3113510400

Appears in sequences

• Order of alternating group A_n, or number of even permutations of n letters.at n=13A001710
• Order of shuffle group on n cards {0..n-1} generated by i->n-1-i and i->min{2i,2n-1-2i}.at n=12A014767
• Denominator of Sum_{k=0..n} 1/k!.at n=13A061355
• a(n) = n! / d(n), where d(n) is the number of divisors of n.at n=12A062358
• Denominators of nonzero terms in the expansion of sin(x)+exp(x)-1-2*x.at n=8A068878
• Order of the subgroup of the symmetric group S_n generated by the cycles (1,2,3) and (1,2,3,...,n).at n=10A070734
• Surface area of n-dimensional sphere of radius r is n*V_n*r^(n-1) = n*Pi^(n/2)*r^(n-1)/(n/2)! = S_n*Pi^floor(n/2)*r^(n-1); sequence gives denominator of S_n.at n=28A072479
• Number of labeled cyclic subgroups of S_n having the maximum possible order.at n=16A074260
• a(n) = p(n)!/2 where p(n) is the upper member of n-th pair of twin primes.at n=2A082670
• Number of topological types of polygons with 2n different sides.at n=6A085990
• Denominator of Laguerre(n, -1).at n=13A160618
• Numbers of the form (k!*(k+1))/2 with k or (k+1) prime.at n=9A177138
• G.f.: Sum_{n>=0} (1 + n*x)^n * x^n / (1 + x + n*x^2)^n.at n=24A187741
• Row sums of 1-Euler triangle A188587.at n=12A188588
• a(1) = a(2) = 1; for n >= 2, a(n) is the product of number k <= n such that GCQ_A(n, k) >= 2 (see definition in comments).at n=12A196442
• Triangular array read by rows: T(n,k) is the number of 2-regular labeled graphs on n nodes that have exactly k connected components (cycles); n>=3, 1<=k<=floor(n/3).at n=26A201013
• Pairs p, q for those partial sums p/q of the series e = sum_{n>=0} 1/n! that are not convergents to e.at n=23A233044
• Triangular array: row n gives the coefficients of the polynomial p(n,x) defined in Comments.at n=41A249253
• a(n) = prime(n+1)! / (prime(n+1) - prime(n))!.at n=4A261523
• Partial products of A265111.at n=19A265125