262800
domain: N
Appears in sequences
- Let f(x) = (Pi - 2*arctan(1/(sqrt(x)*sqrt(x+2))))/(2*sqrt(x)*sqrt(x+2)), take (-1)^n*(n-th derivative from right at x=0) and multiply by A001147(n+1).at n=5A034405
- a(n) = Sum_{d|6} phi(d)*n^(6/d).at n=8A054605
- a(n) = Sum_{d|n} phi(d)*8^(n/d).at n=6A054615
- Triangle T(n,k) = Sum_{d|k} phi(d)*n^(k/d).at n=33A054619
- a(n) = n^2*(n+1)*(3*n+1)/4.at n=24A213827
- a(n) = (-1)^(n+1)*n!* [x^n](log(x + 1)/2 + log(3*x + 1)/6).at n=7A321398
- Expansion of e.g.f. -log( 1 - (exp(x) - 1)^3 / 3! ).at n=7A346390
- Coreful triperfect numbers: numbers k such that csigma(k) = 3*k, where csigma(k) is the sum of the coreful divisors of k (A057723).at n=20A364990
- A005117(k) - 1 where k is the least k such that A389412(k) = n.at n=43A389879