-2809
domain: Z
Appears in sequences
- Expansion of (1-x)^(-1)/(1+2*x+x^2+x^3).at n=15A077930
- Abundances of A188484(n).at n=4A188487
- Expansion of Product_{k>=1} 1/(1 - x^(2*k) + x^(3*k)).at n=29A276526
- Expansion of q * f(-q^1, -q^6)^3 / f(-q^2, -q^5)^2 * f(-q^3, -q^4) in powers of q where f() is Ramanujan's two-variable theta function.at n=43A305443
- Dirichlet g.f.: 1 / zeta(s-2).at n=52A334657
- a(1) = 1, a(2) = -5; a(n) = -n^2 * Sum_{d|n, d < n} a(d) / d^2.at n=52A359485
- a(1) = 1, a(2) = 3; a(n) = n^2 * Sum_{d|n, d < n} (-1)^(n/d) a(d) / d^2.at n=52A361986
- a(1) = 1; a(n) = n^2 * Sum_{d|n, d < n} (-1)^(n/d) a(d) / d^2.at n=52A361987