180544

Appears in sequences

• Length of period of continued fraction for square root of 1+n!.at n=12A078145
• Numbers n such that sigma(n)/tau(n) is a perfect number.at n=19A219179
• Numbers n such that sigma(n) + phi(n) is a composite number of the form p^k where p is a prime.at n=12A230770
• a(n) = (n^4 + 5*n^3 + 11*n^2 + 7*n)/6.at n=31A332697
• Dirichlet g.f.: (zeta(s-3) / zeta(s))^2.at n=29A338165
• Number of permutations in symmetric group S_n with an even number of cycles of length 2 or more.at n=9A373339
• Triangle read by rows: T(n,k) = number of permutations in symmetric group S_n with an even number of non-fixed point cycles, without k<=n particular fixed points.at n=45A374419