2450448

Appears in sequences

• a(n) = (3*n)! / ((n+1)*(n!)^3).at n=6A007004
• Denominator of the n-th alternating harmonic number, Sum_{k=1..n} (-1)^(k+1)/k.at n=16A058312
• Denominator of the n-th alternating harmonic number, Sum_{k=1..n} (-1)^(k+1)/k.at n=17A058312
• Denominators of partial sums of reciprocals of lcm(1..n) = A003418(n).at n=17A064858
• Denominator of Sum_{k=1..n} 1/(n+k).at n=8A082688
• Denominator of n-th term of the harmonic series after removal of all terms 1/m from Sum_{m=1..n} 1/m for which m contains a 9 in its decimal representation.at n=17A111936
• Denominator of n-th term of the harmonic series after removal of all terms 1/m from Sum_{m=1..n} 1/m for which m contains a 9 in its decimal representation.at n=18A111936
• Denominator of n-th term of the harmonic series after removal of all terms 1/m from Sum_{m=1..n} 1/m for which m contains a 9 in its decimal representation.at n=19A111936
• Denominator of the polynomial A_l(x) = sum_{d=1..l-1} x^(l-d)/d for index l=2n+1 evaluated at x=5.at n=8A145618
• Late-growing permutations: number of permutations of 6 indistinguishable copies of 1..n with every partial sum <= the same partial sum averaged over all permutations.at n=2A147692
• Denominators of s(i) = s(i-1) - (1/i)*sign(s(i-1)) with s(1) = 1.at n=16A203811
• Denominators of s(i) = s(i-1) - (1/i)*sign(s(i-1)) with s(1) = 1.at n=17A203811
• a(n) = 132*binomial(n,12).at n=18A213380
• Number of permutations of 0..floor((n*3-1)/2) on even squares of an n X 3 array such that each row and column of even squares is increasing.at n=11A215287
• Number of permutations of 0..floor((n*3-2)/2) on odd squares of an n X 3 array such that each row and column of odd squares is increasing.at n=11A215294
• Number A(n,k) of permutations of k indistinguishable copies of 1..n with every partial sum <= the same partial sum averaged over all permutations; square array A(n,k), n>=0, k>=0, read by antidiagonals.at n=48A215561
• Minimal possible denominator for a sum of the form 1 +/- 1/2 +/- 1/3 +/- ... +/- 1/n.at n=16A232090
• Denominator of sum of fractions A182972(k) / A182973(k) such that A182972(k) + A182973(k) = n.at n=16A245678
• Numbers n such that there exists a pair x,y, where x<y, x! = n and y! = n, that makes {x,y,n,n} an amicable multiset.at n=5A273969
• Triangle read by rows: T(n,k) = binomial(2*n,2*k)*binomial(2*n-2*k,n-k)/(n+1-k) for 0<=k<=n.at n=48A280580