18051406831
domain: N
Appears in sequences
- a(n) = (1/1 - 1/2 + ... + (-1)^(n-1)/n)*lcm{1..n}.at n=25A025530
- Numerator of the n-th alternating harmonic number, Sum_{k=1..n} (-1)^(k+1)/k.at n=25A058313
- Let u(1) = x and u(n+1) = (n^2/u(n)) + 1 for n >= 1; then a(n) is such that u(n) = (b(n)*x + c(n))/(a(n)*x + d(n)) (in lowest terms) and a(n), b(n), c(n), d(n) are positive integers.at n=26A075830
- Numerator of Sum_{k=1..n} 1/(n+k).at n=12A082687
- Numerator of the fraction n*Sum_{k=1..n} 1/(n+k).at n=12A117731
- Numerator of the product of n and the n-th alternating harmonic number, Sum_{k=1..n} (-1)^(k+1)/k.at n=25A119787
- Absolute value of numerator of the sum of all elements of the n X n matrix M with M[i,j] = (-1)^(i+j)*i/j for i,j = 1..n.at n=25A120301