1361360

Appears in sequences

• a(n) = (1/C(2n,0) - 1/C(2n,1) + ... + d/C(2n,2n))*L, where d = (-1)^2n, L = LCM{C(2n,0), C(2n,1),..., C(2n,2n)}.at n=8A025535
• Denominators of a(n+1) = Sum_{k=1..n} a'(n/k), a(1)=1, where a'(x)=a(x) if x integer and is linearly interpolated otherwise.at n=36A071796
• Denominator of n*sum(k=1,(-1)^(k+1)/(n+k)).at n=8A082690
• LCM of terms in Collatz (3x+1) function initiated at n.at n=6A087226
• LCM of terms in Collatz (3x+1) function initiated at n.at n=13A087226
• a(h) = d(h,j) = lcm( f(h,j,1) ... f(h,j,h) ), when j=2.at n=11A097382
• Denominator of b(n), where Sum_{k>=1} b(k)/k^r = 1/(Sum_{k>=1} H(k)/k^r). H(k) = Sum_{j=1..k} 1/j, the k-th harmonic number.at n=17A097504
• Denominator of sum of all elements M(i,j,k) = i*j/k, (i,j,k = 1..n). a(n) = Denominator[Sum[Sum[Sum[i*j/k,{i,1,n}],{j,1,n}],{k,1,n}]].at n=17A099866
• 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=15A111936
• Denominator of Sum_{i=1..n} 1/(i*C(2*i,i)).at n=9A112100
• Denominators of third-order harmonic numbers (defined by Conway and Guy, 1996).at n=16A124838
• a(n) = lcm{1 <= k <= n, gcd(k, 3) = 1}.at n=17A128501
• a(n) = lcm{1 <= k <= n, gcd(k, 3) = 1}.at n=18A128501
• Denominator of Sum_{k=1..n} k*H_{n+k} where H_m = Sum_{i=1..m} 1/i.at n=18A144655
• Denominator of sum of reciprocals of numbers less than n that do not divide n.at n=17A281086
• a(n) is the period of the periodic k-sequence q_k=lcm(k+1,k+2,...,k+n)/(n*binomial(k+n,n)).at n=17A319404
• T(n, k) = (n + k - 1)*(n + k)*binomial(2*n + 1, n - k + 1) with T(0, 0) = T(1, 0) = 1. Triangle read by rows, T(n, k) for 0 <= k <= n.at n=36A342313
• T(n, k) = (n + k - 1)*(n + k)*binomial(2*n + 1, n - k + 1) with T(0, 0) = T(1, 0) = 1. Triangle read by rows, T(n, k) for 0 <= k <= n.at n=39A342313
• a(n) = (n+1)*(3*n-2)*C(2*n,n-1)/(4*n-2).at n=9A352626
• Triangle T(n, m) = (n - m + 1)*C(2*n + 1, m)*C(2*n - m + 2, n - m + 1)/(2*n - m + 2).at n=39A360651