12640320

Appears in sequences

• Number of permutations in the symmetric group S_n that have odd number of transpositions in their cycle decomposition.at n=11A088506
• G.f.: A(q) = exp( Sum_{n>=1} sigma(n) * 3*A038500(n) * q^n/n ), where A038500(n) = highest power of 3 dividing n.at n=22A163129
• A trisection of A163129.at n=7A163131
• T(n, k) = Sum_{j=0..k} (-1)^j*binomial(2*k, j)*(k - j)^(2*n), triangle read by rows, n >= 0 and 0 <= k <= n.at n=25A304330
• Triangle T(n,k) defined by Sum_{k=1..n} T(n,k)*u^k*x^n/n! = Product_{j>0} ( exp(x^j/(1 - x^j)) )^u.at n=38A338864
• Table read by ascending antidiagonals: T(n, k) is the maximum number of quasi k-gons that are not k-gons in a finite projective plane of order n, with k >= 3.at n=22A342307
• Numbers k achieving record abundance (sigma(k) > 2*k) via a residue-based measure M(k) (see Comments), analogous to superabundant numbers A004394.at n=30A362081
• Numbers k that have a record number of divisors that have the same binary weight as k.at n=31A381069
• a(n) = Sum_{j = 1..n} (-1)^(n+j) * j^(2*n+4) * binomial(2*n, n-j).at n=3A382527
• a(n) = Sum_{k=0..n} (-1)^k * binomial(2*n, k) * (n-k)^(3*n).at n=4A383929